Serum Leptin Level Is Reduced in Non-Obese Subjects with Type 2 Diabetes


avatar Ghorban Mohammadzadeh ORCID 1 , * , avatar Nosratollah Zarghami 2

Hyperlipidemia Research Center, Department of Clinical Biochemistry, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences,, IR Iran
Drug Applied Research Center, Tabriz University of Medical Sciences, IR Iran

how to cite: Mohammadzadeh G, Zarghami N. Serum Leptin Level Is Reduced in Non-Obese Subjects with Type 2 Diabetes. Int J Endocrinol Metab. 2013;11(1): 3-10.



Leptin, a protein released from adipose tissue, could have significant role in pathogenesis of obesity and type 2 diabetes mellitus.


This study aimed to evaluate variations in serum leptin levels in non-obese subjects with type 2 diabetes mellitus (T2DM).

Patients and Methods:

We studied forty-one patients with type 2 diabetes. Fasting lipid profile, Hemoglobin A1c (HbA1c), serum leptin, insulin, and glucose levels were measured by standard methods.


The serum leptin level in type 2 diabetic patients (19.32 11.43 ng/mL) was significantly lower than that in non-diabetic subjects (32.16 11.02 ng/mL). Serum leptin level was strongly and positively correlated with body mass index (BMI) (r = 0.658, P < 0.0001) and calculated body fat percentage (r = 0.431, P < 0.0001) in all the study subjects with a better corrlation in the control subjcts compared to control cases (r = 0.661 for BMI and r = 0.466 for body fat). On the other hand, leptin showed a positive and significant correlation with insulin and HOMA- ? (homeostasis model assessment for ?-cell function) in both groups. Furthermore, leptin related to homeostasis model assessment for insulin resistance (HOMA-IR) (r = 0.422, P = 0.006) was observed only in T2DM subjects. Leptin showed negative correlation with waist to hip ratio in diabetic (r = -0.407, P =0.008) and non-diabetic subjects (r = -0.318, P =0.049). In the regression model, BMI, HOMA-?, and gender were independent predictors of leptin in all subjects. However, in non-diabetic and diabetic subjects, ?-cell function and insulin were independent predictors, respectively (P =0.01).


It is speculated that lower serum leptin levels in diabetic patients may be a consequence of male gender. Moreover, results suggest that serum leptin level in women is influenced differently than that in men.

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