Higher Leptin Levels are Associated with Obesity and Slower HIV Disease Progression
Authors: Martinez Sabrina Sales , Campa Adriana , Marlink Richard , Makhema Joseph , Moyo Sikhulile , Huffman Fatma , Baum Marianna K 
Published: November 2023

Background

Leptin is considered to be a pleiotropic molecule, with a role in metabolism, endocrine and immune regulation. Higher levels of leptin have been found in obese individuals thought to enhance the immunity through its role in proliferation and anti‐apoptotic effects on lymphocytes. Leptin has also been inversely associated with HIV viral load, independent of adipose tissue. The objective of this study was to evaluate over 18 months the relationship of leptin with body composition and laboratory markers of HIV disease infection and progression in HIV+ asymptomatic adults who were not receiving ART in Botswana.

Methods

A retrospective cross‐sectional analysis of data and specimens from a nutritional study was conducted in 60 HIV+ ART‐naïve adults who were in the early stages of HIV disease in Botswana, Africa. Anthropometrics and bioimpedance were obtained. Blood was drawn for plasma leptin, CD4 count and %, and HIV viral load. Viral load was stratified into <4 log10 copies/mL and ≥ 4 log10 copies/mL as a measure of faster disease progression and infectivity. BMI was stratified into two groups: normal weight (BMI=18.0–24.9 kg/m2) and overweight/obese (BMI=≥ 25 kg/m2) for the statistical analyses. Plasma leptin levels were measured using the Quantikine Human Leptin Immunoassay kit by R&D systems (Minneapolis, MN, USA), a sandwich ELISA designed to measure soluble human leptin in plasma, according to manufacturer's instructions. Regression analyses were adjusted for age, gender, fat mass% and smoking.

Results

The median age was 33 years with an IQR of 29–39 years and 76.40% were women. Log transformed leptin was associated with continuous BMI at baseline (β=1.764; 95% CI= 0.788, 2.739; P=0.022) and 18 months (β=2.739; 95% CI= 1.133, 3.075, P<0.001). Overweight/obese BMI category was also associated with leptin above the median at baseline (OR=58.572, 95% CI= 2.187, 1568.688; P=0.015) and 18 months (OR=79.634; 95% CI= 4.607, 1376.659; P=0.003). Having a viral load of <4 log10 copies/mL was associated with higher leptin levels (β= −0.305; 95% CI=−0.579, −0.031; P=0.030) at baseline. Leptin above the median was also associated with having an increase in CD4% over 18 months (OR=1.456; 95% CI=1.456, 1.025, 2.069; P=0.036).

Conclusions

We confirmed the relationship between increased BMI and plasma levels of leptin in an HIV infected population. In addition, however, we showed an inverse relationship between leptin levels and viral load at baseline, independent of body fat. Leptin is involved in the proliferation of CD4 and CD8 cells, and leptin levels above the median were associated with a greater increase in CD4% over 18 months. These results indicate that leptin may indeed play a role in the association between body composition, HIV viral replication and CD4 cell count in this HIV+ adult population in Botswana, early in their disease.

Support or Funding Information

NIDA and the Academy of Dietetics and Nutrition