Objective: To determine the relationship between concentration of serum leptin and age in females, and to establish the reference value and compare it with other races.
Methods: Serum leptin concentration of 690 adult healthy women (aged 20 approximately 81 years) was measured with ELISA.
Results: The serum leptin concentration increased with age (r=0.224, P<0.001), and cubic regression was the best-fitting model. Leptin concentration had significant positive correlation with weight (r=0.574) and body mass index (r=0.618). The geometric mean of leptin concentration in normal weight, overweight and obesity was (8.94+/-1.82), (17.6+/-1.89), and (34.7+/-1.69) microg/L, respectively, with significant difference among the 3 groups (P<0.001). Leptin in pre-menopause, peri-menopause and post-menopause women was (9.68+/-1.81), (11.7+/-1.89), and (11.4+/-2.21) microg/L, respectively. The reference value of serum leptin in normal weight females was 5.30 approximately 12.6 microg/L. The curve-fitting of leptin with age in this group was significantly lower than American non Hispanic White (NHW), non Hispanic Black (NHB), and American Mexican (AM) females.
Conclusion: This study provides reliable reference value of serum leptin in adult women and discovers ethnic difference with American NHW, NHB, and AM females.