beta-carotene and Diabetes-Mellitus

Oxidation is a biochemical process of loss of electrons associated with another of reception called reduction. This process is capital for life, because it takes part in the production of cellular energy. Oxidative stress appears when oxidation is excessive. This reality is complex in all biological levels, and cannot be measured or defined by a single parameter. A great number of diseases have been related to oxidative stress and generation of free radicals. For this reason, antioxidant therapies and diets (such as mediterranean diet) rich or enriched with antioxidants seem to prevent or at least to attenuate the organic deterioration originated by an excessive oxidative stress.

Topics: Acute Kidney Injury; Aged; Aging; Antioxidants; Arteriosclerosis; Ascorbic Acid; beta Carotene; Cataract; Diabetes Mellitus; Diet; Humans; Hypertension; Liver Diseases; Neoplasms; Oxidation-Reduction; Oxidative Stress; Primary Prevention; Risk Factors; Selenium; Vitamin E

Considerable interest has risen in the idea that oxidative stress is instrumental in the etiology of numerous human diseases. Oxidative stress can arise through the increased production of reactive oxygen species (ROS) and/or because of a deficiency of antioxidant defenses. Antioxidant deficiencies can develop as a result of decreased antioxidant intake (such as vitamins C and E), synthesis of enzymes (such as superoxide dismutase and glutathione peroxidase) or increased antioxidant utilization. Insufficient antioxidant enzyme synthesis may in turn be due to decreased micronutrient availability (such as selenium, magnese, copper and zinc). Of those diseases linked with oxidative stress, cardiovascular disease provides the strongest evidence for the protective role of antioxidants. A high consumption of fruit and vegetables, which are good sources of antioxidants, is associated with a lower coronary risk. More specifically, there is evidence of a reduced coronary risk in populations with high blood levels of the antioxidant nutrients, vitamins C and E. Evidence is also accumulating that diabetes, and microvascular complications associated with diabetes, involve oxidative stress and have compromised antioxidant status. In addition, patients who develop acute respiratory distress syndrome (ARDS) also exhibit clear evidence of oxidative stress. Definitive proof for active oxygen formation and oxidative cell damage being causative rather than a result of other underlying these pathologies remains elusive; however, evidence is sufficiently compelling to suggest that antioxidants are potential therapeutic agents in the above conditions.

Topics: Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Diabetes Mellitus; Humans; Oxidative Stress; Respiratory Distress Syndrome; Vitamin E

To determine whether alpha-tocopherol or beta-carotene supplementation affects diabetic macrovascular complications and total mortality.. This study was carried out as part of the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, a double-blind, randomized trial with a 2x2 factorial design. A total of 29,133 middle-aged male smokers received either vitamin E 50 mg/day or beta-carotene 20 mg/day, or both, or placebo for a median of 6.1 years. At base-line, 1700 men had type 2 diabetes. Of these men, 662 were diagnosed with first-ever macrovascular complication, and 1142 died during the 19-year follow-up.. Neither supplementation affected the risk of macrovascular complication or total mortality during the intervention period. For the alpha-tocopherol-supplemented versus no alpha-tocopherol-supplemented, and beta-carotene-supplemented versus no beta-carotene-supplemented we found relative risk (RR) 0.84 (95% confidence interval (CI) 0.65-1.10) and RR 1.15 (95% CI 0.89-1.50) for macrovascular complication, respectively, and RR 1.00 (95% CI 0.80-1.25) and RR 1.06 (95% CI 0.85-1.33) for total mortality, respectively. No essential changes were found in these effects when the follow-up was extended up to 19 years.. Alpha-tocopherol or beta-carotene supplementation has no protective effect on macrovascular outcomes or total mortality of diabetic male smokers.

Topics: Aged; alpha-Tocopherol; beta Carotene; Coronary Disease; Diabetes Mellitus; Diabetic Angiopathies; Double-Blind Method; Finland; Humans; Male; Middle Aged; Peripheral Vascular Diseases; Smoking; Stroke; Survival Rate; Treatment Outcome; Vitamins

It has been suggested that increased intake of various antioxidant vitamins reduces the incidence rates of vascular disease, cancer, and other adverse outcomes.. 20,536 UK adults (aged 40-80) with coronary disease, other occlusive arterial disease, or diabetes were randomly allocated to receive antioxidant vitamin supplementation (600 mg vitamin E, 250 mg vitamin C, and 20 mg beta-carotene daily) or matching placebo. Intention-to-treat comparisons of outcome were conducted between all vitamin-allocated and all placebo-allocated participants. An average of 83% of participants in each treatment group remained compliant during the scheduled 5-year treatment period. Allocation to this vitamin regimen approximately doubled the plasma concentration of alpha-tocopherol, increased that of vitamin C by one-third, and quadrupled that of beta-carotene. Primary outcomes were major coronary events (for overall analyses) and fatal or non-fatal vascular events (for subcategory analyses), with subsidiary assessments of cancer and of other major morbidity.. There were no significant differences in all-cause mortality (1446 [14.1%] vitamin-allocated vs 1389 [13.5%] placebo-allocated), or in deaths due to vascular (878 [8.6%] vs 840 [8.2%]) or non-vascular (568 [5.5%] vs 549 [5.3%]) causes. Nor were there any significant differences in the numbers of participants having non-fatal myocardial infarction or coronary death (1063 [10.4%] vs 1047 [10.2%]), non-fatal or fatal stroke (511 [5.0%] vs 518 [5.0%]), or coronary or non-coronary revascularisation (1058 [10.3%] vs 1086 [10.6%]). For the first occurrence of any of these "major vascular events", there were no material differences either overall (2306 [22.5%] vs 2312 [22.5%]; event rate ratio 1.00 [95% CI 0.94-1.06]) or in any of the various subcategories considered. There were no significant effects on cancer incidence or on hospitalisation for any other non-vascular cause.. Among the high-risk individuals that were studied, these antioxidant vitamins appeared to be safe. But, although this regimen increased blood vitamin concentrations substantially, it did not produce any significant reductions in the 5-year mortality from, or incidence of, any type of vascular disease, cancer, or other major outcome.

Topics: Adult; Aged; Aged, 80 and over; Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Cause of Death; Cholesterol; Coronary Disease; Diabetes Mellitus; Female; Follow-Up Studies; Humans; Male; Middle Aged; Neoplasms; Severity of Illness Index; Stroke; United Kingdom; Vitamin E

An inverse association between moderate alcohol consumption and coronary heart disease (CHD) has been observed in several epidemiological studies. To assess whether a similar association exists among diabetics, we examined the relation between light to moderate alcohol consumption and CHD in men with and without diabetes mellitus in a prospective cohort study.. A total of 87 938 US physicians (2790 with diagnosed diabetes mellitus) who were invited to participate in the Physicians' Health Study and were free of myocardial infarction, stroke, cancer, or liver disease at baseline were followed for an average of 5.5 years for death with CHD as the underlying cause. During 480 876 person-years of follow-up, 850 deaths caused by CHD were documented: 717 deaths among nondiabetic men and 133 deaths among diabetic men. Among men without diabetes at baseline, the relative risk estimates for those reporting rarely/never, monthly, weekly, and daily alcohol consumption were 1.00 (referent), 1.02, 0. 82, and 0.61 (95% CI 0.49 to 0.78; P for trend <0.0001) after adjustment for age, aspirin use, smoking, physical activity, body mass index, and history of angina, hypertension, and high cholesterol. Among men with diabetes at baseline, the relative risk estimates were 1.00 (referent), 1.11, 0.67, and 0.42 (95% CI 0.23 to 0.77; P for trend=0.0019).. These results suggest that light to moderate alcohol consumption is associated with similar risk reductions in CHD among diabetic and nondiabetic men.

Topics: Alcohol Drinking; Aspirin; beta Carotene; Cardiovascular Diseases; Coronary Disease; Diabetes Mellitus; Double-Blind Method; Humans; Hypercholesterolemia; Hypertension; Longitudinal Studies; Male; Middle Aged; Multivariate Analysis; Neoplasms; Physicians; Platelet Aggregation Inhibitors; Risk Factors

Among apparently healthy men, elevated levels of C-reactive protein (CRP), a marker for systemic inflammation, predict risk of myocardial infarction and thromboembolic stroke. Whether increased levels of CRP are also associated with the development of symptomatic peripheral arterial disease (PAD) is unknown.. Using a prospective, nested, case-control design, we measured baseline levels of CRP in 144 apparently healthy men participating in the Physicians' Health Study who subsequently developed symptomatic PAD (intermittent claudication or need for revascularization) and in an equal number of control subjects matched on the basis of age and smoking habit who remained free of vascular disease during a follow-up period of 60 months. Median CRP levels at baseline were significantly higher among those who subsequently developed PAD (1.34 versus 0.99 mg/L; P=.04). Furthermore, the risks of developing PAD increased significantly with each increasing quartile of baseline CRP concentration such that relative risks of PAD from lowest (referent) to highest quartile of CRP were 1.0, 1.3, 2.0, and 2.1 (Ptrend=.02). Compared with those with no clinical evidence of disease, the subgroup of case patients who required revascularization had the highest baseline CRP levels (median= 1.75 mg/L; P= .04); relative risks from lowest to highest quartile of CRP for this end point were 1.0, 1.8, 3.8, and 4.1 (Ptrend=.02). Risk estimates were similar after additional control for body mass index, hypercholesterolemia, hypertension, diabetes, and a family history of premature atherosclerosis.. These prospective data indicate that among apparently healthy men, baseline levels of CRP predict future risk of developing symptomatic PAD and thus provide further support for the hypothesis that chronic inflammation is important in the pathogenesis of atherothrombosis.

Topics: Adult; Aged; Aged, 80 and over; Antioxidants; Arteriosclerosis; Aspirin; beta Carotene; Body Mass Index; C-Reactive Protein; Cyclooxygenase Inhibitors; Diabetes Mellitus; Double-Blind Method; Heart Diseases; Humans; Hypercholesterolemia; Intermittent Claudication; Male; Middle Aged; Myocardial Revascularization; Peripheral Vascular Diseases; Prospective Studies; Reference Values; Risk Factors

Epidemiologic evidence regarding the role of dietary vitamin A in the development of diabetes is limited and inconsistent. This study was to explore the association between vitamin A intake and diabetes risk in Chinese adults.. A prospective cohort study was conducted among 17 111 adults (8537 men and 8577 women) who participated in the China Health and Nutrition Survey between 1989 and 2015. Dietary intakes were assessed by 3 consecutive 24-hour dietary recalls combined with a household food inventory. Diabetes was determined by self-reported diagnosis, diabetes medication use, or additional criterion in 2009 of fasting blood glucose or hemoglobin A1c. We analyzed the association of vitamin A intake (total, β-carotene, retinol) with diabetes risk using Cox proportional hazards models.. A total of 519 men and 531 women developed diabetes during a median of 11 years of follow-up. Higher dietary total vitamin A intakes were associated with a lower risk of diabetes in both men (quintile 5 [Q5] vs Q1: hazard ratio [HR] = 0.69, 95% CI, 0.49-0.97, P-trend = 0.079) and women (Q5 vs Q1: HR = 0.63; 95% CI, 0.45-0.89; P-trend = 0.039). An inverse relation with diabetes risk was observed for dietary intakes of β-carotene (Q5 vs Q1: HR = 0.71; 95% CI, 0.52-0.97) and retinol (Q5 vs Q1: HR = 0.58; 95% CI, 0.39-0.85) among men, but not women. Dose-response analyses showed the association of dietary intakes of total vitamin A, β-carotene, and retinol with diabetes risk in men was L-shaped (P-nonlinearity = 0.043), reverse J-shaped (P-nonlinearity = 0.001), and linear, respectively.. Our findings suggest that adequate intake of vitamin A may help protecting against diabetes, especially for men.

Topics: Adult; beta Carotene; Blood Glucose; Diabetes Mellitus; Diet; Diet, Vegetarian; Glycated Hemoglobin; Humans; Male; Prospective Studies; Risk Factors; Vitamin A

Although the health effects of beta carotene have been studied extensively, a systematic examination of serum concentrations and long-term mortality, including cardiovascular disease mortality, has not been reported.. Explore whether serum beta carotene is associated with overall and cause-specific mortality and to elucidate the strength and dose-response of the association.. We conducted a prospective serological analysis of 29 103 men in the ATBC study (Alpha-Tocopherol, Beta-Carotene Cancer Prevention). During 31 years of follow-up, 23 796 deaths occurred, including deaths because of cardiovascular disease (9869), cancer (7692), respiratory disease (2161), diabetes mellitus (119), injuries and accidents (1255), and other causes (2700). Serum beta carotene was assayed using high-performance liquid chromatography. Adjusting for major risk factors measured, men with higher serum beta carotene had significantly lower all-cause mortality (hazard ratios=0.81, 0.71, 0.69, and 0.64 for quintile 2 (Q2)-Q5 versus Q1, respectively; P. This study provides evidence that higher beta carotene biochemical status is associated with lower overall, cardiovascular disease, heart disease, stroke, cancer, and other causes of mortality. The dose-response associations over a 30-year period were not attenuated by adjustment for other important risk factors and support greater fruit and vegetable consumption as a means to increase beta carotene status and promote longevity.

Topics: Aged; beta Carotene; Cardiovascular Diseases; Diabetes Mellitus; Finland; Humans; Male; Middle Aged; Mortality; Neoplasms; Respiratory Tract Diseases; Wounds and Injuries

Many epidemiological studies find an inverse correlation between carotenoids intake or carotenoids plasma concentrations and body mass index (BMI), insulin resistance or metabolic syndrome in the general population. However, it is not clear whether these relationships occur in obese population.. We conducted a cross-sectional study in 108 obese non-diabetic patients.. There was an inverse correlation between plasma levels of pro-vitamin A carotenoids (α-carotene, β-carotene and β-cryptoxanthin) and both BMI and insulin resistance (estimated by the HOMA-IR). No correlation between plasma concentrations of lycopene or lutein/zeaxanthin and BMI or insulin resistance was found. The inverse association between the three pro-vitamin A carotenoids and HOMA-IR disappeared after adjustment for BMI and waist circumference. Interestingly, we identified a positive association between concentrations of β-carotene and adiponectin in plasma that was independent of sex, age, smoking status, BMI and waist circumference. To our knowledge, such association has never been described in obese patients.. These results suggest the existence of a favourable effect of β-carotene on insulin sensitivity in obese individuals that could involve a positive regulation of adiponectin, either directly or via its pro-vitamin A activity. The demonstration of the potential benefits of β-carotene towards insulin sensitivity would open the way to dietary strategies to prevent metabolic syndrome.

Topics: Adiponectin; Adolescent; Adult; Aged; beta Carotene; Body Mass Index; Carotenoids; Cholesterol, HDL; Cholesterol, LDL; Cross-Sectional Studies; Diabetes Mellitus; Diet; Female; Humans; Insulin Resistance; Interleukin-1; Leptin; Linear Models; Lutein; Lycopene; Male; Metabolic Syndrome; Middle Aged; Multivariate Analysis; Obesity; Plasminogen Activator Inhibitor 1; Triglycerides; Tumor Necrosis Factor-alpha; Young Adult; Zeaxanthins

Topics: Attitude of Health Personnel; beta Carotene; Biomarkers; Diabetes Mellitus; Diet; Dietary Supplements; Female; Humans; Hypertension; Male; Nutrition Assessment; Randomized Controlled Trials as Topic; Reproducibility of Results; Sex Characteristics

Antioxidants are potentially beneficial in preventing vascular complications in diabetes because oxidative stress would be enhanced in such a condition and play an important role in vascular disorders. This study aimed to investigate whether brachial-ankle pulse wave velocity (baPWV) would be lower in the presence of high serum carotenoid concentrations stratified according to the glycemic state. A total of 297 men and 579 women between 30 and 70 years of age were analyzed cross-sectionally. Multivariate adjusted mean of baPWV in the highest tertile for beta-carotene (1386 cm/s) was lower than that in the lowest tertile (1432 cm/s) and that in the highest tertile for beta-cryptoxanthin (1382 cm/s) was lower than that in the middle tertile (1424 cm/s) in the case of normal fasting glucose. Similar inverse associations were observed in a group that included subjects with both impaired fasting glucose and diabetes, however, without statistical significance. The highest tertile of carotenoids was associated with a low risk for high baPWV (> or =1680 cm/s). Age, sex and glycemic state adjusted odds ratio was 0.35 (95% CI 0.20-0.60) for beta-carotene and 0.45 (0.27-0.77) for beta-cryptoxanthin. Multivariate adjustment did not alter the results. In conclusion, an inverse association of baPWV with beta-carotene and beta-cryptoxanthin was observed independently of the glycemic state.

Topics: Adult; Aged; Arteriosclerosis; beta Carotene; Biomarkers; Blood Flow Velocity; Blood Glucose; Brachial Artery; Cross-Sectional Studies; Cryptoxanthins; Diabetes Mellitus; Disease Progression; Female; Follow-Up Studies; Humans; Male; Middle Aged; Prognosis; Pulsatile Flow; Retrospective Studies; Tibial Arteries; Xanthophylls

Smoking is associated with low serum carotenoid concentrations. Prospective studies have found lower diabetes risk among persons with high-carotenoid diets. Whether diabetes risk is low in the rare smoker who has high serum carotenoid levels is unknown. The authors investigated the interaction of serum carotenoid concentrations and smoking with diabetes mellitus in 4,493 Black and White men and women aged 18-30 years in the Coronary Artery Risk Development in Young Adults (CARDIA) Study. The authors assessed 15-year (1985-2001) incident diabetes (148 cases), insulin concentration, and insulin resistance (homeostasis model assessment) in smokers and nonsmokers according to baseline levels of serum alpha-carotene, beta-carotene, zeaxanthin, beta-cryptoxanthin, and lycopene. Diabetes incidence was inversely associated with the sum of carotenoid concentrations in nonsmokers (per standard deviation (SD) increase, relative hazard = 0.74, 95% confidence interval: 0.55, 0.99) but not in current smokers (relative hazard = 1.13, 95% confidence interval: 0.83, 1.53) (p for interaction = 0.02). Similarly, year 15 insulin and insulin resistance values, adjusted for baseline levels, were inversely related to sum of carotenoids only in nonsmokers (per SD increase in insulin level, slope = -0.46 (p = 0.03); per SD increase in insulin resistance, slope = -0.14 (p = 0.01)). In CARDIA, higher serum carotenoid concentrations are associated with lower risk of diabetes and insulin resistance in nonsmokers but not in smokers.

Topics: Adolescent; Adult; beta Carotene; Black People; Carotenoids; Cryptoxanthins; Diabetes Mellitus; Female; Humans; Incidence; Insulin Resistance; Lycopene; Male; Proportional Hazards Models; Prospective Studies; Risk Factors; Smoking; White People; Xanthophylls; Zeaxanthins

Our objectives were to explore novel metabolic risk factors for development of heart failure (HF).. In the past decade, considerable knowledge has been gained from limited samples regarding novel risk factors for HF, but the importance of these in the general population is largely unexplored.. In a community-based prospective study of 2,321 middle-aged men free from HF and valvular disease at baseline, variables reflecting glucose and lipid metabolism and variables involved in oxidative processes were compared with established risk factors for HF (prior myocardial infarction, hypertension, diabetes, electrocardiographic left ventricular hypertrophy, smoking, obesity, and serum cholesterol) using Cox proportional hazards analyses.. During a median follow-up time of 29 years, 259 subjects developed HF. In a multivariable Cox proportional hazards backward stepwise model, a 1-SD increase of fasting proinsulin (hazard ratio [HR] 1.38, 95% confidence interval [CI] 1.15 to 1.66) and apolipoprotein B/A-I-ratio (HR 1.27, 95% CI 1.09 to 1.48) increased the risk, whereas a 1-SD increase in serum beta-carotene (HR 0.79, 95% CI 0.66 to 0.94) decreased the risk of HF. These variables also remained significant when adjusting for acute myocardial infarction during follow-up.. Novel variables reflecting insulin resistance and dyslipidemia, together with a low beta-carotene level, were found to predict HF independently of established risk factors. If confirmed, our observations could have large clinical implications, as they may offer new approaches in the prevention of HF.

Topics: Antioxidants; Apolipoproteins; beta Carotene; Comorbidity; Diabetes Mellitus; Heart Failure; Humans; Insulin Resistance; Male; Middle Aged; Oxidative Stress; Prognosis; Proinsulin; Proportional Hazards Models; Prospective Studies; Risk Factors

Smoking is an established risk factor for ischemic stroke and subarachnoid hemorrhage (SAH), but the impact of smoking on intracerebral hemorrhage (ICH) is less clear.. Prospective cohort study among 22,022 US male physicians participating in the Physicians' Health Study. Incidence of stroke was measured by self-report and confirmed by medical record review. We used Cox proportional-hazards models to evaluate the association of smoking with risk of total hemorrhagic stroke, ICH, and SAH. We categorized smoking into 4 groups: never, past, or current smokers of <20 or of >or=20 cigarettes per day.. During 17.8 years of follow-up, 108 ICHs and 31 SAHs occurred. Never smokers and past smokers had equal rates of ICH and SAH. Current smokers of <20 cigarettes per day had multivariable-adjusted relative risks of 1.65 (95% CI, 0.61 to 4.50) for total hemorrhagic stroke, 1.60 (95% CI, 0.50 to 5.07) for ICH, and 1.75 (95% CI, 0.24 to 13.09) for SAH when compared with never smokers. Current smokers of >or=20 cigarettes had relative risks of 2.36 (95% CI, 1.38 to 4.02) for total hemorrhagic stroke, 2.06 (95% CI, 1.08 to 3.96) for ICH, and 3.22 (95% CI, 1.26 to 8.18) for SAH when compared with never smokers.. This prospective study suggests an increased risk of total hemorrhagic stroke, ICH, and SAH in current cigarette smokers with a graded increase in risk that depended on how many cigarettes were smoked. The effect of smoking on ICH is of about the same magnitude as the effect of smoking on ischemic stroke. Our results add to the multiple health benefits that can be accrued by abstaining from cigarette smoking.

Topics: Adult; Age Factors; Aged; Aged, 80 and over; Alcohol Drinking; Aspirin; beta Carotene; Body Mass Index; Brain Ischemia; Cardiovascular Diseases; Cerebral Arteries; Cerebral Hemorrhage; Cohort Studies; Comorbidity; Confounding Factors, Epidemiologic; Diabetes Mellitus; Exercise; Follow-Up Studies; Humans; Hypercholesterolemia; Hypertension; Incidence; Male; Medical Records; Middle Aged; Multivariate Analysis; Neoplasms; Physicians; Proportional Hazards Models; Prospective Studies; Randomized Controlled Trials as Topic; Risk; Smoking; Stroke; Subarachnoid Hemorrhage; United States

The association between dietary and lifestyle factors and intermittent claudication was investigated in the Finnish Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. The cohort comprised 26,872 male smokers aged 50-69 years who were free of claudication at study entry. At baseline (1985-1988), subjects completed a diet history questionnaire. During a median follow-up period of 4 years (ending in spring 1993), 2,578 men reported symptoms of claudication on the Rose questionnaire, which was administered annually. Smoking status was assessed every 4 months. Smoking, systolic blood pressure, serum total cholesterol, and diabetes mellitus were positively associated with risk for claudication, whereas serum high density lipoprotein cholesterol, education, and leisure time exercise were inversely associated with risk. Dietary carbohydrates, fiber, and n-6 polyunsaturated fatty acids were inversely associated with risk for claudication, as were some dietary and serum antioxidants: dietary vitamin C (highest quartile vs. lowest: relative risk (RR) = 0.86; 95% confidence interval (CI): 0.77, 0.97), dietary gamma-tocopherol (RR = 0.89; 95% CI: 0.79, 1.00), dietary carotenoids (RR = 0.82; 95% CI: 0.73, 0.92), serum alpha-tocopherol (RR = 0.88; 95% CI: 0.77, 1.00), and serum beta-carotene (RR = 0.77; 95% CI: 0.68, 0.86). Smoking cessation reduced subsequent risk for claudication (RR = 0.86; 95% CI: 0.75, 0.99). The authors conclude that classical risk factors for atherosclerosis are associated with claudication. High intakes of antioxidant vitamins may be protective. Further research is needed before antioxidants can be recommended for the prevention of intermittent claudication.

Topics: Administration, Oral; Age Distribution; Aged; Ascorbic Acid; beta Carotene; Blood Pressure; Cholesterol; Cholesterol, HDL; Cohort Studies; Comorbidity; Diabetes Mellitus; Dietary Supplements; Energy Metabolism; Finland; Humans; Incidence; Intermittent Claudication; Life Style; Male; Middle Aged; Multivariate Analysis; Prospective Studies; Risk Assessment; Risk Factors; Smoking; Smoking Cessation; Vitamin A; Vitamin E

Little is known about carotenoids, a diverse group of plant compounds with antioxidant activity, and their association with diabetes, a condition characterized by oxidative stress. Data from phase I of the Third National Health and Nutrition Examination Survey (1988-1991) were used to examine concentrations of alpha-carotene, beta-carotene, cryptoxanthin, lutein/zeaxanthin, and lycopene in 40- to 74-year-old persons with a normal glucose tolerance (n = 1,010), impaired glucose tolerance (n = 277), newly diagnosed diabetes (n = 148), and previously diagnosed diabetes (n = 230) based on World Health Organization criteria. After adjustment for age, sex, race, education, serum cotinine, serum cholesterol, body mass index, physical activity, alcohol consumption, vitamin use, and carotene and energy intake, geometric means of beta-carotene were 0.363, 0.316, and 0.290 micromol/liter for persons with a normal glucose tolerance, impaired glucose tolerance, and newly diagnosed diabetes, respectively (p = 0.004 for linear trend), and geometric means for serum lycopene were 0.277, 0.259, and 0.231 micromol/liter, respectively (p = 0.044 for linear trend). All serum carotenoids were inversely related to fasting serum insulin after adjustment for confounders (p < 0.05 for each carotenoid). If confirmed, these data suggest new opportunities for research that include exploring a possible role for carotenoids in the pathogenesis of insulin resistance and diabetes.

Topics: Adult; Aged; Antioxidants; beta Carotene; Carotenoids; Case-Control Studies; Cryptoxanthins; Diabetes Mellitus; Female; Glucose Intolerance; Glucose Tolerance Test; Humans; Lutein; Lycopene; Male; Middle Aged; Nutrition Surveys; Regression Analysis; United States; Xanthophylls

Topics: Adult; Aged; Aged, 80 and over; beta Carotene; Diabetes Mellitus; Diet; Humans; Male; Middle Aged

Risk factors for pancreatic cancer were examined in a cohort study of 13,979 residents of a retirement community. After 9 years of follow-up, 65 incident cases of pancreatic cancer were identified. An increased risk of pancreatic cancer was associated with a history of diabetes and cholecystectomy. Higher intake of vegetables, fruits, dietary beta-carotene, and vitamin C were each associated with a reduced risk of pancreatic cancer, although none of these associations was statistically significant. Risk of pancreatic cancer decreased with increasing tea consumption but was unrelated to coffee consumption. No strong or consistent association was seen between either smoking or alcohol consumption and risk of pancreatic cancer, but a consistent and significant increase in risk followed cholecystectomy.

Topics: Aged; Aged, 80 and over; Alcohol Drinking; Ascorbic Acid; beta Carotene; Carotenoids; Cholecystectomy; Coffee; Cohort Studies; Diabetes Mellitus; Diet; Female; Follow-Up Studies; Fruit; Humans; Incidence; Male; Pancreatic Neoplasms; Prospective Studies; Risk Factors; Smoking; Tea; Vegetables

Studies indicate that large doses of all-rac-alpha-tocopherol in people with diabetes or ascorbic acid in nondiabetic subjects reduces protein glycosylation. The mechanisms by which these nutrients influence glycosylation are poorly understood but may be related to their ability to function as antioxidants. We examined the relationship between glycosylated hemoglobin (GHb) and intake of vitamins E and C and beta-carotene in a population-based sample of middle-aged and older adults participating in the Beaver Dam Eye Study. In people with diabetes, no significant associations were observed between GHb and intake of vitamins E and C and beta-carotene. In people without diabetes, energy-adjusted vitamin C intake was negatively associated with GHb after age and sex were controlled for (dietary, P = 0.02; total, P = 0.04). No significant relationships between GHb and intake of vitamin E and beta-carotene were observed.

Topics: Adult; Aged; Aged, 80 and over; Aging; Ascorbic Acid; beta Carotene; Carotenoids; Diabetes Mellitus; Diet; Female; Glycated Hemoglobin; Humans; Male; Middle Aged; Osmolar Concentration; Vitamin E