Introduction:Type 2 diabetes mellitus (DM) is one of the leading non-communicable causes of death in the Philippines with a prevalence of 5.4% and its pathogenesis includes insulin resistance correlated with excess weight and BMI. Asian-based studies have shown that serum C-peptide is strongly associated with newly diagnosed diabetes and has a linear increasing trend with BMI, hence, this study aimed to determine the correlation of body mass index (BMI) with fasting C-peptide levels in Filipino patients with newly diagnosed type 2 DM. Also, to determine the correlation of fasting C-peptide, markers of insulin secretion and sensitivity (Homeostasis Model Assessment of beta cell function and insulin resistance: HOMA-IR, HOMA-B) with other metabolic parameters in newly diagnosed diabetics: waist circumference, HbA1C, fasting blood sugar (FBS), lipid profile.

Methods:This cross-sectional study included 35 treatment naïve, newly diagnosed type 2 DM Filipino patients evaluated with anthropometric measurements, fasting C-peptide, and other metabolic parameters. The correlations among fasting C-peptide, BMI, waist circumference, FBS, HbA1c, lipid profile, HOMA-IR, and HOMA-B were determined using Pearson correlation.

Results:A significant positive relationship were observed between BMI and HOMA-IR(r=0.335); C-peptide and waist circumference (r=0.363); C-peptide and HOMA-B(r=0.357); HOMA-IR and C-peptide (r=0.892); HOMA-IR and waist circumference (r=0.438); HOMA-IR and triglycerides (r=0.543). HOMA-B was negatively correlated with FBS and HbA1C (r=- 0.771, and r=-0.641, respectively). No correlation was seen between BMI and C-peptide (p=0.61).

Conclusion:Body mass index (BMI) is not correlated with fasting C-peptide levels in newly diagnosed type 2 DM Filipino patients. The positive relationship between C-peptide, waist circumference, and HOMA-IR merits further evaluation with larger studies.