Normalizing circulating leptin levels might reduce cardiovascular risk in patients with chronic kidney disease mineral bone disorder (CKD-MBD).
Reduced heart rate variability (HRV) has been observed in CKD patients and possibly reflects impaired cardiac automatic nervous function and high risk of cardiovascular disease (CVD). Circulating leptin levels potentially influence this sympathetic nervous activity. Previous research has linked abnormally low and high leptin with worse health: hypoleptinemia has been linked to malnutrition and hyperleptinemia may be a uremic toxin.
Yao Jiang, MD, of the First Affiliated Hospital with Nanjing Medical University in China, and colleagues investigated whether parathyroidectomy improves leptin levels and HRV in CKD patients with secondary hyperparathyroidism (SHPT). They performed a cross-sectional study of 141 SHPT patients, then prospectively followed 36 who underwent total parathyroidectomy (PTx) with autotransplantation for 6 months. HRV was measured by 24-hour Holter recordings of electrocardiograms. No patients were treated with calcimimetics.
Patients were grouped into quartiles by their leptin levels and body mass index (BMI) adjusted for gender. Results showed no difference in HRV among quartiles. However, patients in the Q1 group had a non-significantly higher heart rate and lower levels of the very low frequency component of HRV than other quartiles. The very low frequency measure improved after PTx.
A multivariate analysis identified serum leptin/BMI as an independent predictor of the low frequency/high frequency ratio of HRV, an indication that leptin is associated with cardiac nervous system function. HRV indices and leptin/BMI levels improved with PTx.
“We suggest that proper regulation on circulating leptin level may substantially improve the decreased HRV and reduce the risk of CVD in CKD patients…” Dr Jiang and colleagues wrote in the American Journal of Nephrology. “Circulating leptin levels may be a novel treatment target to reduce CVD risk in advanced CKD-MBD patients.”
Since the study was observational, future studies are warranted to confirm the findings.
1. Yao Jiang a Zhixiang Shen c Jingjing Zhang, et al. Parathyroidectomy Increases Heart Rate Variability and Leptin Levels in Patients with Stage 5 Chronic Kidney Disease. Am J Nephrol 2016;44:245–254d. doi: 10.1159/000449018.