The Relationship between Family History and C-peptide Level in Type2 Diabetic Patients

Abstract

Background: Family history of type 2 diabetes is a major risk factor for type 2 diabetes. Type 2 diabetes is characterized by progressive β-cell dysfunction; many investigators have used C peptide levels as a biomarker of β-cell function.

Objective: the current study was design to investigate the impact of family history on biochemical characteristics (c-peptide, HbA1c, lipid profile, insulin secretion, insulin sensitivity and insulin resistance.

J Fac Med Baghdad

2013; Vol.55, No .3

Received Feb .2013

Accepted July.2013

Subjects and methods: three hundreds patients (152 males 148 females) with type 2 DM were enrolled in this study; and two hundreds individual serves as a control groups (103 male 97 female). The following clinical characteristics were reported: age, sex, waist circumference WC, systolic blood pressure SBP, diastolic blood pressure DBP, family history, body mass index BMI, laboratory analyses included serum c-peptide, blood glycosylated hemoglobin (HbA1c) assay, lipid profile which included serum cholesterol, serum triglyceride(TG), serum low density lipoprotein cholesterol (LDL) and serum high density lipoprotein-cholesterol (HDL). Insulin secretion, sensitivity and resistance were calculated from fasting serum glucose (FSG) (mg/dl) and C-peptide (ng/ml) values by homeostasis model assessment (HOMA).The statistical analysis was done by SPSS (statistical packagefor social sciences- version 17).

Result: Statistically was observed that highly significant increase in serum C-peptide in patients compared to control group (3.85±1.02 vs 1.53±0.24 p<0.01).The patients with a family history of type 2 diabetes mellitus had longer diabetes duration, heavier weight, higher levels of TG, LDL-cholesterol, and lowered age, HDL-cholesterol than those without a family history . Also, the presence of a family history of diabetes was associated with lower levels of fasting plasma C-peptide (3.01± 1.78 vs 4.95±1.82, p<0.05). Serum C-peptide had a significant negative correlation with family history and duration of diabetes. Furthermore, C-peptide was inversely correlated with HbA1c, and insulin sensitivity (HOMA-S). On the other hand, C-peptide correlated positively with BMI, DBP, LDL-cholesterol, TG, insulin resistance HOMA-IR, and insulin secretion HOMA-B. As well as, C-peptide did not show significant correlation with age, FSG, and TC. When the multiple linear analysis was executed with C-peptide as dependent variable with other independent variable (BMI, duration, family history, HOMA-IR, HOMA-S, and HOMA-B) there were significant result with this variables. The person correlation analyses to identify the parameters that most closely related with diabetic duration according to family history of diabetes; which showed that diabetic duration had a significant negative correlation with C-peptide, and HOMA-B only in patients with family history of Type2 DM (-0.126, and -0.229) respectively.

Conclusion: the current study suggested that subjects with a family history of diabetes mellitus are predisposed to develop this disease earlier. Although, serum C-peptide increased significantly in diabetics group compared with controls, and C-peptide decreased in patients with family history of diabetes. In addition, the results showed that family history of type2 diabetic patients is thought to have a deep impact on duration of the disease, lipid profile, insulin resistance, insulin sensitivity, and this may lead to higher prevalence of diabetic complication compared to patients without family history. These results support the necessity of earlier screening for diabetes in family members of T2DM patients and prevention the complications of the disease.