Effects of weight loss on bone turnover, inflammatory cytokines, and adipokines in Chinese overweight and obese adults

Purpose: Plenty of studies have examined the long term effect of weight loss on bone mineral density. This study aimed to explore the effects of 10% weight loss on early changes in bone metabolism as well as the possible influencing factors.

Methods: Overweight and obese outpatients (BMI > 24.0 kg/m²) were recruited from the nutrition clinic and followed a calorie-restricted, high-protein, low-carbohydrate diet program. Dietary intake, body composition, serum procollagen type I N-propeptide (PINP), β-Crosslaps, PTH, 25(OH) VitD, a series of inflammatory cytokines and adipokines were measured for the participants before starting to lose weight and after 10% weight loss (NCT04207879).

Results: A total of 75 participants were enrolled and 37 participants achieved a weight loss of at least 10%. It was found that PINP decreased (p = 0.000) and the β-Crosslaps increased (p = 0.035) in female participants. Decreases in PTH (p = 0.001), serum IL-2 (p = 0.013), leptin (p = 0.001) and increases in 25(OH) VitD (p = 0.001), serum ghrelin (p = 0.033) were found in 37 participants after 10% of their weight had been lost. Change in PINP was detected to be significantly associated with change in lean body mass (r = 0.418, p = 0.012) and change in serum ghrelin(r = - 0.374, p = 0.023).

Conclusions: Bone formation was suppressed and bone absorption was increased in female subjects after a 10% weight loss. Bone turnover was found to be associated with lean body mass and affected by the circulating ghrelin level.