Hormone Levels Linked to Metabolic Disease

An association has been found between low levels of a specific hormone and increased risk of metabolic disease in humans.

The peptide hormone adropin is required for metabolic homeostasis and prevention of obesity-associated insulin resistance and is thought to play a vital role in controlling sugar levels and fatty acid metabolism.

A multicenter study led by scientists at The Scripps Research Institute (Jupiter, FL, USA), which included 85 women and 45 men, was carried out to measure adropin levels in serum or plasma in duplicate using a commercially available enzyme-linked immunosorbent assay (ELISA). The lowest detection limit was 0.2 ng/mL and the intraassay coefficient of variation (CV) determined using quality-control human plasma samples with adropin values ranging from 1.1–2.4 ng/mL, was 8.6%.

Lower adropin levels were seen in people with a higher metabolic syndrome risk factor score. This score is based on measuring triglycerides, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL), glucose, blood pressure, and waist circumference. The data suggest that levels of adropin in plasma are stable over time and do not exhibit marked diurnal or meal-related variations. Adropin concentrations increased after Roux-en-Y gastric bypass, peaking three months after surgery. In all subjects, lower age-adjusted adropin levels of 3.3 ng/mL were observed in overweight and 2.7 ng/mL in obese patients compared with 4.1 ng/mL for healthy-weight subjects.

In patients of normal weight, women had lower plasma adropin levels than men, while obesity had a greater adverse effect on adropin levels in men. Obesity in woman was also not connected with lower plasma adropin levels. The team also discovered that adropin levels generally decline with age and was greatest in people over 30 years of age and this was more evident in the male patients. The adropin ELISA used in the study is a product of Peninsula Laboratories, (Bachem; San Carlos, CA, USA).

Andrew A. Butler, Ph., the senior author of the study, said, "The data from these studies provide strong evidence suggesting that low levels of adropin may be an indicator of risk for insulin resistance in obesity and, consequently, an increased risk for metabolic diseases, including type 2 diabetes. We see a lot of similarity between animal model data and the new human data-low adropin levels in humans are associated with a host of metabolic syndrome risk factors normally associated with obesity and insulin resistance." The study was published on August 7, 2012, in the Journal of Clinical Endocrinology and Metabolism.

Related Links:
The Scripps Research Institute
Peninsula Laboratories