ObjectivesSubclinical hypothyroidism is the precursor to hypothyroidism because it has a tendency to transform into hypothyroidism. Subclinical hypothyroidism is considered one of the risk factors causing metabolic syndrome. Metabolic syndrome can be characterized by plasma levels of apelin and lipocalin-2, both released from adipocytes. In the present study, we aimed to measure serum apelin and lipocalin-2 levels of patients with subclinical hypothyroidism and compare them with serum apelin and lipocalin-2 levels from healthy individuals. MethodsThis was a cross-sectional study. A total of 80 subjects were enrolled in the study and divided into two groups: Group A included 39 patients (females, n=34) diagnosed with subclinical hypothyroidism, and Group B (the control group) comprised 41 healthy volunteers (females, n=38). Serum samples were obtained from each participant for the measurement of apelin and lipocalin-2. These were then stored at minus 80°C until the time of analysis, when serum apelin and lipocalin-2 levels of the two groups were compared. ResultsPatients with subclinical hypothyroidism (Group A and Group B subjects [healthy controls]) were comparable with respect to gender, age, and body mass index (BMI) (P=0.412, P=0.863, and P=0.269, respectively), nor was there a statistically significant difference between groups in terms of apelin and lipocalin-2 levels (P=0.87, and P=0.67, respectively). Apelin levels showed a positive and significant correlation with BMI (P=0.034). Serum lipocalin-2 levels showed significant positive correlations with BMI and creatinine levels (P=0.002, and P=0.025, respectively). ConclusionIn the present study, no significant difference of serum apelin and lipocalin-2 levels was observed between patients with subclinical hypothyroidism and healthy control subjects. Positive correlations were found, however, between serum apelin level and BMI as well as between serum lipocalin-2 and BMI and creatinine levels.