The leptin to adiponectin ratio (LAR) is reduced by sleeve gastrectomy in adults with severe obesity: a prospective cohort study

Bariatric surgery is known to reduce leptin and increase adiponectin levels, but the influence of sleeve gastrectomy on the leptin: adiponectin ratio (LAR), a measure of insulin sensitivity and cardiovascular risk, has not previously been described. We sought to determine the influence of sleeve gastrectomy on LAR in adults with severe obesity.In a single centre prospective cohort study of adults undergoing laparoscopic sleeve gastrectomy over a four-month period in our unit, we measured LAR preoperatively and 12 months after surgery. Of 22 patients undergoing sleeve gastrectomy, 17 (12 females, 12 with type 2 diabetes) had follow-up LAR measured at 12.1 ± 1 months. Mean body weight decreased from 130.6 ± 30.8 kg to 97.6 ± 21.6 kg, body mass index (BMI) from 46.9 ± 7.8 to 35.3 ± 7.2 kg m⁻² and excess body weight from 87.5 ± 31.3 to 41.3 ± 28.8% (all p < 0.001). The reduction in leptin from 40.7 ± 24.9 to 30.9 ± 30.5 ng/ml was not significant (p = 0.11), but adiponectin increased from 4.49 ± 1.6 to 8.93 ± 6.36 µg/ml (p = 0.005) and LAR decreased from 8.89 ± 4.8 to 5.26 ± 6.52 ng/µg (p = 0.001), equivalent to a 70.9% increase in insulin sensitivity. The correlation with the amount of weight lost was stronger for LAR than it was for leptin or adiponectin alone. In this single-centre, interventional prospective cohort, patients undergoing laparoscopic sleeve gastrectomy had a substantial reduction in their LAR after 12 months which was proportional to the amount of weight lost. This may indicate an improvement in insulin sensitivity and a reduction in cardiovascular risk.