Blood leptin concentration lacks comprehensive reference values for clinical and research use. To address this gap, a study established reference ranges across age, pubertal status, and body weight status (normal to extreme obesity), involving 12,629 individuals, aged 0–75 years. The study found that leptin concentrations rose in boys from ages 6 to 12 before declining after age 12, while in girls, levels increased until age 15 with BMI-dependent patterns thereafter.
Overall, leptin was higher in girls than in boys, except in boys aged 9–15 years with a BMI-SDS > 3. In adults, women showed consistently higher leptin across BMI categories, whereas in men levels declined into early adulthood until the mid-20s for BMI 30 kg/m² and until age 50 for BMI 40 kg/m² before stabilizing. These findings suggest that this study provides the first reference curves for leptin concentrations across the…
