Endocrine Abstracts

Introduction: In contrast to general population, clinical consequences related to low levels of 25-hydroxyvitamin D in HIV-infected patients with overweight are not established. The aim of our study was to investigate the influence of weight on clinical parameters and on calcium-phosphorus homeostasis in HIV-patients with vitamin D deficiency.

Methods/design: Prospective study of HIV outpatients treated in our hospital. Vitamin D deficiency (D-DEF) was defined as serum 25-hydroxyvitamin D below 20 ng/ml. Patients were classified as “overweight/obesity” if body mass index (BMI) ≥25 Kg/m². Their clinical, metabolic and immunological data were compared to HIV-individuals classified as “normal weight” (BMI: 18.5–24.9 Kg/m²).

Results: One hundred and six HIV-infected individuals (86.8% male, mean age: 46.4±6.5 years) were included. 51.9% were classified as “overweight/obese”. Levels of vitamin D were lower in “overweight/obese”, but no significant difference was observed between both groups (14.8±4 vs 15.3±1.8 ng/mL; P=0.772). In overweight HIV-patients, although into the normal range, the serum phosphorus levels were higher as compared as those without D-DEF (3.3±0.8 vs 2.9±0.5 mg/dl; P=0.04). Levels of i-PTH were also higher in overweight D-DEF patients (66.1±35.1 vs 48.9±19.8 pg/ml; P=0.04). No others differences were observed between these groups. Analyzing individuals with D-DEF only, there was no difference in calcium, phosphorus or i-PTH levels between patients with or without overweight.

Conclusions: In HIV-infected patients with low levels of 25-hydroxyvitamin D, BMI ≥25 Kg/m² determines subtle changes on calcium-phosphorus homeostasis which clinical significance remains to be determined. Further follow-up studies to establish potential clinical implications of these findings are needed.