Relationship of leptin concentration to gender, body mass index and age in Saudi adults.
Level 4 - case-series / case-control
Cross-sectional observational study
What was done
A cross-sectional study in Jeddah, Saudi Arabia, measured fasting serum leptin concentrations in 122 healthy adults (57 women, 65 men; age range 20-75 years; BMI range 16-56 kg/m2). Participants were stratified by sex, BMI categories (lean 15-24, overweight 25-30, obese >30 kg/m2), and age groups (20-34, 35-49, 50-75 years). Blood pressure, fasting glucose, and anthropometric metrics (weight, height, waist, and hip circumferences) were collected to assess the relationship between leptin, adiposity metrics, sex, and age.
What was found
Total leptin levels ranged from 0.16 to 21.72 ng/ml. Women had significantly higher circulating leptin than men (6.04 +/- 4.71 ng/ml vs. 1.72 +/- 0.95 ng/ml, p < 0.0001), a difference that persisted across BMI and age subgroups. Leptin correlated positively with BMI in both women (r = 0.64, p = 0.0001) and men (r = 0.49, p = 0.0001). With increasing age, leptin showed a non-significant decrease in women and a significant increase in men (p = 0.05). In stepwise multiple linear regression, leptin was independently predicted by BMI and age in women (r = 0.69, p = 0.015), and by BMI, age, and waist-to-hip ratio in men (r = 0.61, p = 0.01).
Why it matters
The study confirms that sexual dimorphism in leptin levels and the positive relationship between leptin and BMI observed in other populations are consistent in a Saudi adult cohort.
Limits
The sample size was modest (122 participants total, further subdivided into age and BMI strata). As a single-center, cross-sectional observational study, it cannot establish causality or track changes over time. Body composition was estimated via anthropometric proxies rather than direct fat mass imaging.
Cited by
- context When equating for BMI, women require higher circulating leptin levels than men to experience satiety due to higher brain resistance to leptin signaling.