Hashtag bone: detrimental effects on bone contrast with metabolic benefits one and five years after Roux-en-Y gastric bypass

Abstract

Bone loss is a potential adverse consequence of rapid and sustained weight loss after bariatric surgery. The aim of the present study was to evaluate the bone mass, body fat distribution, and metabolic parameters in women submitted to Roux-en-Y gastric bypass (RYGB). The study included the following three groups: one group of lean women (control [C] group) and two groups of obese women, one evaluated one year (B1) and the other five years (B5) after RYGB. Dual-energy X-ray absorptiometry and magnetic resonance imaging were used to determine bone mineral density (BMD; lumbar spine, total hip, and femoral neck) and abdominal fat content (subcutaneous [SAT] and visceral [VAT] adipose tissues, and intrahepatic lipids [IHL]). The BMD/body mass index ratio was lower in the B5 compared with the C group at all sites. Serum C-terminal telopeptide of type I collagen (CTX) levels were higher in the B1 and B5 groups compared with the C group. Individuals submitted to RYGB showed greater SAT but similar VAT and IHL values compared with those in the C group. However, the B5 group had higher mean parathyroid hormone levels compared with the other two groups. Individuals submitted to RYGB presented increased levels of CTX and low BMD for body weight than those in the C group, suggesting that bone catabolism is a persistent alteration associated with RYGB. In conclusion, the long-lasting metabolic benefits obtained with RYGB in obesity are counterbalanced by a persistent catabolic effect of the procedure on bone and mineral metabolism.

Bone, fat, and muscle interactions in health and disease

“…There is a paucity of prospective data evaluating both the bone loss and metabolic benefits of bariatric surgery in severely obese individuals ( 72 ). However, a recent cross-sectional study has shown metabolic benefits obtained with bariatric surgery, which persist for 5 years after the procedure, even in patients whose BMI remains in the range of obesity.…”

“…After bariatric surgery, the VAT/SAT distribution ratio and the amount of IHL were similar in individuals with obesity or normal weight. In contrast, individuals submitted to bariatric surgery present early elevation of remodeling marker of bone resorption, a pattern that is maintained for at least 5 years after surgery ( 72 ). Two previous studies, one cross-sectional ( 72 ) and the other prospective ( 73 ), have suggested precocious and sustained increased levels of the biochemical marker of bone resorption CTX.…”

“…In the former, Alencar and cols. described that the groups evaluated 1 and 5 years after Roux-en-Y bypass (RYGB) showed levels of serum CTX that were, respectively, 97% and 51% higher than those in the control group ( 72 ). In a prospective study, serum CTX levels have been found to be 150% above the basal levels 5 years after RYGB ( 73 ).…”

“…In a prospective study, serum CTX levels have been found to be 150% above the basal levels 5 years after RYGB ( 73 ). On the other hand, the literature shows more modest or no difference in the biochemical markers of bone formation after bariatric surgery ( 72 , 73 ). For instance, Alencar and cols.…”

Diabetes and bone

“…Multiple pieces of evidence indicate that not only muscle and adipose tissue contribute to the regulation of energy metabolism but that peptides produced by bone cells are also part of the orchestration that involves the metabolic control of glucose, lipids, and proteins (1)(2)(3). Similarly, several hormones are important for the regulation of energy metabolism and influence bone remodeling (e.g., insulin and epinephrine).…”