International Journal of Clinical Biochemistry and Research


A STUDY OF SDLDL-C AND INSULIN RESISTANCE IN APPARENTLY HEALTHY SOUTH INDIAN OBESE YOUNG ADULTS


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Author Details: Viyatprajna Acharya, B D Toora

Volume : 2

Issue : 1

Online ISSN : 2394-6377

Print ISSN : 2394-6369

Article First Page : 41

Article End Page : 47


Abstract

Background: Obesity is now occurring in pandemic proportions and has earned a new name as “Globesity” for it. Unlike earlier times developing countries too are facing the challenge of obesity and the modern epidemics have a common root cause tapering to obesity. Obesity during adolescent and young adulthood usually persists to adulthood in almost 50% cases and gives rise to early onset of type 2 diabetes mellitus, cardiovascular disorders and metabolic syndrome for which insulin resistance being the common link to all.
Objective: The present study was taken up to study the prevalence of insulin resistance in apparently healthy young adult obese population and study its correlation with different cardiovascular risk factors like lipid profile and sdLDL-C.
Material and Methods: In a randomized control study 106 apparently healthy young adults in the age group of 21-34 years were chosen from the community out of which 45 were obese and 61were age and gender matched non-obese controls. They were divided in obese and non-obese groups based on cut-off BMI of 25Kg/m2. Along with physical parameters fasting plasma glucose, lipid profile and routine biochemical parameters were assayed by standard kit methods and plasma insulin was measured by sandwich ELISA method. Different lipid ratios, atherogenic index and insulin resistance were calculated. Atherogenic index was calculated and insulin resistance was measured by HOMA-IR model and QUICKI index. Small dense LDL-C (sdLDL-C) was quantified by modified Tsutomu –Hirano method.
Results: In the obese group BMI, waist circumference (WC) and waist-hip ratio (WHR) elevated significantly (p=0.0001) and TG, VLDL-C and sdLDL-C as well as atherogenic index elevated significantly (p<0.001).Significant Hyperinsulinaemia (p<0.0001) was found in the obese group and 50% of obese cases had hyperinsulinaemia. Insulin resistance calculated by HOMA-IR and QUICKI index was statistically significant (p<0.0001) in obese. Linear regression analysis showed sdLDL-C (R2=0.08, p=0.05 at 95% C.I.), hyperinsulinaemia (R2=0.089, p=0.054 at 95% C.I.) and insulin resistance (R2=0.099, p=0.03 at 95% C.I.) significantly dependent on WC and atherogenic index was significantly dependent on TG (R2=0.0036, p=0.05 at 95% C.I.) rather than any other lipid factors. On ROC analysis either method of insulin resistance showed equal efficacy (AUC for HOMA-IR= 80.3% and QUICKI = 80.14%; C.I. 95%) and atherogenic index turned out to be a better predictor than sdLDL-C (AUC for Atherogenic index= 76.14% and QUICKI = 71.46%).
Conclusions: For Indian subpopulation WC and WHR should also be evaluated along with BMI. Insulin resistance should be identified early and interventional measures should be taken in terms of low carbohydrate protein-rich diet, physical exercise and insulin receptor sensitizers for a short-term. sdLDL-C rises earlier than total cholesterol and hence can be accepted as CVS risk predictor. Not many studies have been done in India on young adult health which is the group that can be targeted for early prevention of the modern epidemics like DM, Metabolic syndrome, CVS disorders and cancers.

Key words: Hyperinsulinaemia, insulin resistance, Small dense-low density lipoprotein, Type-2 diabetes mellitus, metabolic syndrome.