Serum Leptin Concentration Predict Cardiovascular Outcomes in Hemodialysis Patients

Leptin, a 16-kDa protein product mainly secreted by adipocytes, has been known to increase energy expenditure, suppress appetite, and leads to weight loss. Hyperleptinemia was common in maintenance hemodialysis (MHD) patients, and it was likely to be one of the causes of anorexia and malnutrition.

End-stage renal disease (ESRD) is the fifth stage of chronic kidney diseases (CKD) whose effective treatment includes kidney transplantation and dialysis. Hemodialysis could be one of the optimal choices for ESRD patients to obtain a better prognosis. However, cardiovascular events, malnutrition, infection and other complications were still the major factors affecting the prognosis of MHD patients.

Nephrologists at the West China Hospital of Sichuan University (Chengdu, China) enrolled a total of 165 eligible patients with a mean age of 51(range: 43–65) years, 98 (59.4%) were male and 67 (40.6%) were female, in a prospective study to explore the associations between serum leptin concentration and cardiovascular prognosis in maintenance hemodialysis patients. Serum biochemical parameters were recorded based on the blood samples from a routine checkup, which were collected close to the day that body composition assessment was carried out and measured in a central laboratory.

Blood specimens from patients were obtained before a midweek hemodialysis session and immediately prepared for the subsequent leptin concentration tests. After centrifugation at 3,000 rpm for five minutes, serum was extracted and stored at −80° C. The human leptin ELISA kit (American Laboratory Products Company, ALPCO, Salem, NH, USA) was used to measure the serum leptin concentration in duplicate. The detection limit was 0.1 ng/mL. The intra-assay and inter-assay variation were < 3.5% and < 6.4%, which suggested the test method was reliable.

The scientists reported that the mean serum leptin concentration was 35.49 ± 29.98 ng/mL and patients were divided into two groups of serum leptin concentration ≥ 15.31 ng/mL and serum leptin concentration < 15.31 ng/mL by the optimal cut-off point from ROC curve for cardiovascular events (CVEs). During a median follow-up of 18 (12–22) months, CVEs occurred in 37 (22.4%) patients and the cardiovascular and all-cause mortality was 10.9% and 21.82%. Serum leptin concentration was associated with CVEs (hazard ratio [HR] = 0.982), cardiovascular death (CVD) (HR = 0.934) and all-cause death (HR = 0.943). Decreased serum leptin concentration was an independent risk factor for the development of left ventricular hypertrophy (LVH, odds ratio [OR] = 0.98) and peripheral vascular disease (PVD, OR = 0.974).

The authors concluded that serum leptin concentration can independently predict cardiovascular outcomes and all-cause death in MHD patients. They suggest that the effects that serum leptin concentration has on development of LVH and PVD maybe the potential mechanism. The study was published on June 4, 2021 in the journal Clinica Chimica Acta.

Related Links:
West China Hospital of Sichuan University
American Laboratory Products Company