Effects of anthropometric parameters on bone mineral density in women: from perimenopause to old age.

AIM: To analyze the influence of body components on bone mineral density (BMD) in women from perimenopause to old age. MATERIAL AND METHODS: A total of 117 women were allocated into three groups according to the reproductive stage (STRAW): perimenopausal (PEM, N = 28, mean age 44.8 ± 3.6), early postmenopausal (EPM, N = 36, mean age 51.4 ± 2.8) and late postmenopausal (LPM, N = 53; mean age 64.0 ± 1.7). Total body mass, body mass index (BMI), lean mass (LM), fat mass (FM), fat percentage (FP) and BMD at the lumbar spine (lBMD) and femoral neck (fBMD) were assessed. RESULTS: BMI, FM, LM and BMD values decreased from PEM to LPM. The total effect of FM on fBMD and lBMD was of 42% and 8% for PEM, 28% and 33% for EMP and 9% and 1% for LPM respectively. Additionally, the total effect of LM on fBMD and lBMD was 48% and 3% for PEM, 54% and 53% for EMP and 9% and 11% for LPM women respectively. CONCLUSION: BMI, LM, and FM decreased with aging. All these components had great influence on both fBMD and lBMD in EMP women. Conversely, in PEM these parameters only had influence on femoral BMD, but not on lumbar spine. These data suggests that LM is the most important component in BMD for women older than 50 years old, particularly in the hip.

Changes in bone mass and body composition after bariatric surgery.

Aim: To analyze the effects of body weight loss on bone mineral density (BMD) on hip (Hip BMD) and lumbar spine (Lumbar BMD) after six months of bariatric surgery. Bariatric surgery is an effective treatment for morbid obesity. Nonetheless, there are scant data on the effect of weight bearing on bone structure.Material and methods: Seventeen obese women aged 41.2 ± 11.3 yrs. who underwent Roux-en-Y gastric bypass (RYGB) were included. Body composition assessments were performed through dual-energy X-ray absorptiometry immediately before and after 6-months RYGB. Data collected pre- and post-RYGB included total body weight, body mass index (BMI), lean body mass (LM), fat mass (FM) and bone mineral content. The pre- (PRE) and post-operative (POST) results were compared.Results: Lumbar BMD POST presented a non-significant loss of 1.8% whereas Hip BMD POST showed a significant loss of 17.8%. The analysis demonstrated that BMI and LM PRE explained 26% and 49%, respectively, of Hip BMD PRE variability. In addition, LM POST explained 30% of hip BMD POST variability and was not significant for Lumbar BMD POST.Conclusions: Obesity and rapid weight loss showed direct influence in Hip BMD after six months of bariatric surgery. However, its effect on the lumbar spine area was smaller due to the higher capacity of the spine to dissipate loads through its curvature.