calcitriol and Diseases-in-Twins

Patients taking antiepileptic drugs (AEDs) have an increased incidence of fractures. This study investigated chronic AED use and physical contributors to falls risk using an AED-discordant, twin and sibling matched-pair approach, and assessed clinically relevant subgroups: AED polytherapy; longer-duration AED; and falls history.. Twenty-nine same-sex (mean age 44.9 years, 59% female), ambulatory, community-dwelling twin and sibling pairs, discordant for AED exposure (and AED-indication), were recruited. Validated clinical and laboratory tests of strength, gait, and balance were performed. Relevant AED levels, and fasting serum samples for 25-hydroxyvitamin D (25OHD), 1,25-dihydroxyvitamin D [1,25(OH)(2)D], and immunoreactive parathyroid hormone (iPTH) levels were taken.. There were significant mean within-pair differences in tests of static and dynamic balance, with the AED user having poorer balance function than the AED nonuser. No difference was seen in lower limb strength or gait measures. Increased duration of AED therapy and AED polytherapy were independent predictors of increased sway. No significant within-pair differences were seen in fasting serum levels of 1,25(OH)(2)D, 25OHD and iPTH after Bonferroni correction.. Balance performance is impaired in AED users compared to their matched nonuser siblings. Pairs where the AED users took AED polytherapy, or had a longer duration of AED use, had more impaired balance performance. These balance deficits may contribute to the increased rate of fractures in this population.

Topics: Accidental Falls; Adult; Anticonvulsants; Diseases in Twins; Drug Therapy, Combination; Epilepsy; Female; Fractures, Bone; Gait; Humans; Male; Muscle Strength; Parathyroid Hormone; Postural Balance; Risk Factors; Siblings; Vitamin D; Vitamin D Deficiency

The extrarenal synthesis of active vitamin D sterols has a central causative role in the hypercalcemia associated with various granulomatous diseases.. To study the calcium metabolism in patients with cat-scratch disease who have hypercalcemia.. Case report.. University hospital in Barcelona, Spain.. Two identical twins who developed asymptomatic hypercalcemia during the acute phase of cat-scratch disease.. Serial measures of calcium homeostasis and metabolism over a 2-month period.. On admission and 6 and 7 days later, both patients were found to have increased levels of serum and urinary calcium, serum phosphate, and serum 1,25-dihydroxyvitamin D [1,25(OH)2D], whereas they had normal values of serum 25-hydroxyvitamin D and urinary cyclic adenosine monophosphate and decreased serum concentrations of intact parathyroid hormone. Sixteen and 20 days after admission, these abnormalities had resolved without treatment. A direct correlation was observed between the serum 1,25(OH)2D levels and both the serum and 24-hour urinary calcium concentrations. Also, the concentrations of calcium and 1,25(OH)2D paralleled the clinical activity of the infectious disease over the period these parameters were measured.. Our cases provide evidence that cat-scratch disease can produce hypercalcemia through the unregulated production of the metabolite 1,25(OH)2D. Cat-scratch disease should be added to the list of granuloma-forming diseases that are responsible for 1,25(OH)2D-mediated hypercalcemia.

Topics: Adolescent; Bartonella henselae; Calcium; Cat-Scratch Disease; Diseases in Twins; Humans; Hypercalcemia; Lymph Nodes; Male; Serologic Tests; Twins, Monozygotic; Vitamin D