Screening for vitamin D deficiency in a tropical area: results of a sun exposure questionnaire

Abstract Background Vitamin D deficiency is pandemic while resources available to measure 25-hydroxyvitamin D (25OHD) are limited. The present study aimed to verify whether sun exposure measured by a structured questionnaire could predict serum 25OHD concentrations in healthy Caucasian individuals living in a tropical area. Methods A cross-sectional study was carried out in subjects living in the greater São Paulo area, Brazil. Two groups of 50 young (20 to 40 years old) and 50 older (60 to 80 years old) subjects (N = 200) answered a structured questionnaire on sun exposure and had blood samples drawn for serum 25OHD concentration measurement during both summer and winter. Anthropometric data were also recorded. Correlation between the questionnaire variables (duration of sun exposure, amount of exposed skin, total sun exposure score - TSES and other data) and serum 25OHD concentration was evaluated. Results Mean serum 25OHD concentration was 17.60 ± 7.3 ng/mL with no difference between age groups (p = 0.293). TSES weakly correlated with serum 25OHD levels (r = 0.264; p < 0.001). Separate analyzes by age groups demonstrated that TSES correlated significantly with serum 25OHD concentration only in the older subjects during summer (r = 0.322; p = 0.023). Using linear regression analyses, TSES and body mass index (BMI) were significantly associated with serum 25OHD levels. On the other hand, Receiver operating characteristic (ROC) analysis for TSES showed no significance as a screening tool for vitamin D deficiency (p = 0.172). Conclusion Sun exposure questionnaire associated with BMI correlates with serum 25OHD concentration with very low accuracy. The use of the questionnaire does not discriminate between vitamin D sufficient and deficient individuals

Impaired bone mineral accrual in prepubertal HIV-infected children: a cohort study

ABSTRACT OBJECTIVE: To evaluate bone mass accrual and determine the influence of clinical, anthropometric, dietary and biochemical parameters on bone mass. METHODS: A cohort study including 35 prepubertal HIV-infected children, between 7 and 12 years, attended at a referral center. At time 1 (T1) and time 2 (T2), patients were assessed according to clinical, anthropometric, dietary, biochemical parameters and bone mineral density (BMD). At T2, patients were divided into prepubertal and pubertal. RESULTS: Despite the increase in bone mass absolute values, there was no improvement in lumbar spine BMD (LSBMD) Z-score (p = 0.512) and worsening in total body BMD (TBMD) Z-score (p = 0.040). Pubertal patients (n = 19) showed higher bone mineral content (BMC) (p = 0.001), TBMD (p = 0.006) and LSBMD (p = 0.002) compared to prepubertal patients. After multivariate linear regression analysis, the predictors of bone mass in T1 were age, BMI and HAZ-scores for BMC; BMI Z-score, adequate serum magnesium concentration and dietary calcium intake for TBMD; adequate serum concentration of magnesium, BMI and HAZ-scores for LSBMD. In T2, age, total body fat and lean body mass (kg) for BMC; BMI Z-score and puberty for TBMD; dietary fat intake, BMI Z-score for BMD and puberty for LSBMD. CONCLUSION: HIV-infected children have compromised bone mass and the presence of puberty seems to provide suitability of these parameters. Adequate intake of calcium and fat appears to be protective for proper bone mass accumulation factor, as well as monitoring nutritional status and serum magnesium concentration

Body composition and lipodystrophy in prepubertal HIV-infected children

OBJECTIVE: To identify lipodystrophy in prepubertal HIV-infected children using anthropometric parameters and body composition assessment. METHODS: Cross-sectional study including 40 prepubertal HIV-infected children of both genders seen at the Care Center of the Division of Pediatric Infectious Diseases - Universidade Federal de São Paulo, São Paulo city, Brazil, was carried out from August to December 2008. Age, clinical and immunological status, prophylaxis, transmission and highly active antiretroviral therapy were recorded. Body mass index z-score and height-for-age z-score were calculated to characterize the nutritional status. Circumferences were measured with flexible tape and skinfolds were assessed by an adipometry. Fat mass and lean mass were determined by dual-energy X-ray absorptiometry. Presence of clinical signs of lipodystrophy was assessed by a trained clinician. Data were analyzed using SPSS 12.0 software. RESULTS: The mean age and standard deviation were 9.8 (1.2) years, 50% were girls and 82.5% children from B and C categories. Clinical lipodystrophy and dislypidemia were present in 27.5% and 70%, respectively. The trunk to arm ratio and the limb to trunk ratio had positive association with lipodystrophy. Patients with lipodystrophy had short stature, higher triglycerides values and lower HDL-cholesterol. CONCLUSION: The ratios obtained by skinfolds and dual-energy X-ray absorptiometry measurements can be considered as indicators of preclinical lipodystrophy. The cutoff points have not been determined yet; however, continuous assessment may be useful to identify early body composition changes