Roux-en-Y gastric bypass and gastric sleeve surgery result in long term bone loss.

OBJECTIVES: Little is known about the long-term skeletal impact of bariatric procedures, particularly the increasingly commonly performed gastric sleeve surgery (GS). We examined bone density (BMD) change following three types of bariatric surgery Roux-en-Y gastric bypass (RYGB), GS and laparoscopic adjustable gastric banding (LAGB), compared with diet, over 36 months. METHODS: Non-randomized, prospective study of participants with severe obesity (n = 52), undergoing weight-loss interventions: RYGB (n = 7), GS (n = 21), LAGB (n = 11) and diet (n = 13). Measurements of calciotropic indices, gut hormones (fasting and post prandial) peptide YY (PYY), glucagon-like peptide 1 (GLP1) and adiponectin together with dual-X-ray absorptiometry and quantitative computed tomography scans were performed thorough the study. RESULTS: All groups lost weight during the first 12 months. Despite weight stability from 12 to 36 months and supplementation of calcium and vitamin D, there was progressive bone loss at the total hip (TH) over 36 months in RYGB -14% (95% CI: -12, -17) and GS -9% (95% CI: -7, -10). In RYGB forearm BMD also declined over 36 months -9% (95% CI: -6, -12) and LS BMD declined over the first 12 months -7% (95% CI: -3, -12). RYGB and GS groups experienced significantly greater bone loss until 36 months than LAGB and diet groups, which experienced no significant BMD loss. These bone losses remained significant after adjustment for weight loss and age. RYGB and GS procedures resulted in elevated postprandial PYY, adiponectin and bone turnover markers up to 36 months without such changes among LAGB and diet participants. CONCLUSIONS: RYGB and GS but not LAGB resulted in ongoing TH bone loss for three postoperative years. For RYGB, bone loss was also observed at LS and non-weight-bearing forearms. These BMD changes were independent of weight and age differences. We, therefore, recommend close monitoring of bone health following RYGB and GS surgeries.

Effects of lifestyle and diet on bone health in young adult Chinese women living in Hong Kong and Beijing.

BACKGROUND: Dietary and lifestyle variations may be too small to detect possible associations with bone mineral density (BMD) within a community. Pooled data from communities with different diets and lifestyle but of the same ethnicity may help explore these associations. OBJECTIVE: To examine the effects of dietary and lifestyle factors on BMD in young Chinese women. METHODS: Baseline data were analyzed from 441 women aged 20 to 35 years in Hong Kong and Beijing who were participating in a longitudinal study evaluating the effect of milk supplementation on bone health. Data on demographic characteristics, lifestyle, use of oral contraceptives, diet, physical activity, and BMD of total hip, femoral neck, and total spine measured by dual-energy x-ray absorptiometry were pooled for analysis. RESULTS: Hong Kong subjects had significantly lower BMD and higher body-size-adjusted dietary intakes of protein, fat, fiber, vitamins, potassium, sodium, and selenium than Beijing subjects. Multivariate regression of pooled data showed that body mass index was the most important determinant of BMD at all sites. Age was negatively associated and use of oral contraceptives was positively associated with femoral neck BMD. Carbohydrate intake was positively associated with total hip BMD. Fiber intake was negatively associated with BMD at total hip and total spine. Increased vitamin E intake was associated with greater total spine BMD. None of the nutrients were associated with BMD at the femoral neck. CONCLUSIONS: Diet, lifestyle, and BMD differed greatly between young women from Hong Kong and Beijing. Body mass index was the most important determinant of BMD in young Chinese women, whereas age, use of oral contraceptives, and diet had less pronounced effects.

Milk supplementation and bone health in young adult chinese women.

BACKGROUND: Milk is potentially beneficial for bone health, particularly for Chinese populations where consumption of dairy products is low. There are few data about milk consumption by Chinese women aged 20-35 years. This study examines whether milk supplement over 2 years caused increased bone mineral density (BMD) in Chinese women aged 20-35 years. METHODS: Four hundred forty-one community-living women living in Hong Kong SAR (221) and Beijing (220) China were randomized to receive milk supplement or nothing. The supplement consisted of two sachets of milk powder (1000 mg calcium, 80 microg vitamin K(1)), for 24 months. BMD at total hip, total spine, and whole body was measured at baseline and at 6, 12, 18, and 24 months; blood specimens were analyzed at baseline and at 3 and 24 months for biochemical indices of bone turnover and vitamin K. Urine samples also were collected. Analysis was by intention to treat as well as per protocol. Differences in change from baseline between the milk and control groups were analyzed using the mixed models approach to repeated measures, including the baseline value as a covariate. RESULTS: Both groups had an increase in BMD and a decrease in bone turnover markers over time, as an indicator of the process of attainment of peak bone mass during this period. Apart from a higher total spine BMD at 6 months in the milk group using per protocol analysis, there was little significant difference observed between the milk group and the control group. CONCLUSIONS: Age-related bone metabolism and lack of compliance most likely explain the lack of consistent changes in BMD or bone biochemical measures in response to milk supplementation for 2 years in Chinese women aged 20-35 years.