Effect of weight loss strategies on FGF21

Weight loss by calorie restriction or Roux-en-Y Gastric bypass surgery (RYGB) is a cornerstone in the current treatment for obesity and diabetes. The anatomical alterations after RYGB and peri-operative starvation could affect endocrine fibroblast growth factors (FGFs)  in a direct manner. This is important as FGF19 and FGF21 have diverse hormone-like metabolic functions. In addition to FGF19 and FGF21,  the early effects of restrictive and metabolic weight loss strategies on (postprandial) bile salt has not been directly compared yet.

Therefore, Lips et al.  investigated the sub-acute effects of RYGB as opposed to calorie restriction by very-low-calorie diet (VLCD) or gastric banding (GB) on these signalling molecules in obese subjects with normal glucose tolerance (NGT) or type 2 diabetes mellitus (T2DM). To elucidate whether RYGB exerts metabolic effects independent of weight loss, they examined subjects within 3 weeks after intervention when weight loss was relatively small and similar among the treatment groups. To address the effect of more pronounced weight loss, they also studied subjects 3 months after the interventions.

They found that calorie restriction by either GB or VLCD lowered bile salt and FGF21 levels whilst, RYGB surgery elevated bile salt and FGF21 levels. They conclude that in view of the beneficial metabolic effects of FGF21, an increase in FGF21 levels after RYGB  may in fact contribute to the beneficial effect of the procedure in ameliorating glucose homeostasis.

Read full article by Lips et al. (2014) Clinical Endocrinology, 81 862-870; DOI: 10.1111/cen.12496