Bone mineral density after bariatric surgery. A systematic review.

PURPOSE: Bone regulation system may be affected after bariatric surgeries, but procedures impact differently to bone mineral density (BMD) and measures restraining bone loss are frequently neglected until clinical consequences become manifest. This is a systematic review aimed to elucidate whether BMD loss is comparable after different bariatric surgeries. MATERIALS AND METHODS: A search of morbid obese adults, undergone to bariatric surgery, with BMD measured by dual-energy X-ray absorptiometry at baseline and after surgery studies was performed in several databases. Studies were assessed using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement and COCHRANE Risk of Bias tool. The random model was selected for meta-analysis; heterogeneity was analyzed with T(2), inconsistency (I(2) > 50%) and Chi(2) (p < 0.10). Level of evidence and strength of recommendations were summarized using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE System). RESULTS: Twelve studies met the selection criteria. After one year, reduction in total BMD in patients with mixed surgical procedures was significant: -0.03 g/cm(2) (CI 95% 0.00 to -0.06, p < 0.05). BMD was reduced by -0.12 g/cm(2) (CI 95% -0.10 to -0.15, p < 0.001) in the hip, -0.07 g/cm(2) (CI 95% -0.03 to -0.11, p < 0.001) in the column, and -0.03 g/cm(2) (IC 95% -0.02 to -0.04, p < 0.001) in the forearm, but not in restrictive surgeries. Studies included showed high heterogeneity and low quality of evidence. CONCLUSIONS: Patients undergone to mixed bariatric surgery had significant higher BMD deterioration as demonstrated in this review, suggesting that more attention for preventing fractures is required.

Association between Apolipoprotein E Variants and Obesity-Related Traits in Mexican School Children.

BACKGROUND/AIM: Genetic variation in apolipoprotein E (ApoE) has a key role in lipid metabolism. However, its contribution to the amount and distribution of body fat is under investigation. The aim of this study was to analyze the association between genetic variation in ApoE and obesity-related traits in Mexican school children. MATERIAL AND METHODS: Anthropometric, body composition and physical activity measures were conducted using standard methods in 300 children (177 girls/123 boys) who fulfilled the inclusion criteria. DNA was isolated from saliva. ApoE genotypes were analyzed by allelic discrimination. The association between variation in ApoE and anthropometric and body composition measures was investigated using the General Linear Model. RESULTS: The mean±SD values for age, body mass index (BMI) and waist circumference (WC) were 9.05±0.80 years, 19.01±3.83 and 67.98±10.97 cm, respectively. Approximately 46% of the participants were overweight or obese. A significant association between ApoE isoforms and WC was found after controlling for age, sex and the percentage of physical activity (p=0.025). Significant main effects were found for vigorous physical activity and light physical activity influencing the adiposity-related BMI (p<0.001) and WC (p=0.044), respectively. CONCLUSIONS: Variation in ApoE and physical activity intensity were associated with adiposity-related phenotypes in Mexican school children.