Background: The neuropeptide kisspeptin has recently been demonstrated to play a role in regulating energy balance and glucose metabolism. Previous studies showed a positive effect of serum kisspeptin in relation to glucose metabolism. These included negative association between serum kisspeptin and body mass index (BMI), homeostatic model assessment of insulin resistance (HOMA-IR) and plasma insulin. However, some studies reported conflicting results. Data on serum kisspeptin in obese children are limited.
Objective: To determine serum kisspeptin in obese children and its relation to glucose metabolism
Methods: There were 133 obese children included. All children underwent an oral glucose tolerance test (OGTT) and had their fasting serum kisspeptin levels measured. Insulin secretion (HOMA-β and insulinogenic index) and insulin sensitivity (whole body insulin sensitivity index and HOMA-IR) indices were assessed using serum glucose and insulin levels derived during the OGTT. Serum kisspeptin in relation to glucose metabolism was analyzed.
Results: Median (IQR) age of enrolled children was 11.8 (10.8, 13.5) years and 57 of them (43%) were males. There were 18 (14%), 83 (62%) and 32 (24%) patients with normal glucose tolerance (NGT), hyperinsulinemia with normal glucose (HI) and abnormal glucose tolerance (AGT), respectively. BMI Z-scores were not different among these 3 groups. Males had higher serum kisspeptin levels than females [68 (37, 83) vs. 48 (25, 73) pg/mL, p = 0.043]. Patients with Tanner stages II & III had higher serum kisspeptin levels than those with Tanner stage I [63 (37, 79) vs. 15 (9, 73) pg/mL, p = 0.049]. Serum kisspeptin levels were not different among the 3 groups of glucose metabolism [NGT: 67 (32, 83), HI: 48 (27, 78) and AGT: 69 (35, 80) pg/mL, p = 0.538]. Serum kisspeptin levels were also not different among the different BMI Z-score tertiles. There were no correlations between serum kisspeptin levels and insulin secretion or insulin sensitivity indices in all children. However, after adjustment for sex and puberty, serum kisspeptin level was negatively associated with fasting plasma glucose (FPG) in the HI group (β = -1.487, p = 0.006).
Conclusion: Serum kisspeptin levels were not different among different glucose metabolism categories. Negative correlation between serum kisspeptin and FPG was only found in the HI group.
19 Sep 2019 - 21 Sep 2019