A Comparative Study of Some Biochemical Parameters in Overweight and Obese Subjects and their Relation to Ferritin and Insulin Resistance Index

Abstract

Prior researches have suggested that obesity/overweight may be associated with certain biochemical abnormalities. As this has important clinical implications, in line with this, this research is conducted to bring out the effect of overweight and obesity across different age categories on blood pressure and important biochemical parameters. In addition, the research investigated the association of C reactive protein, serum ferritin in relation to BMI and insulin resistance (HOMA-IR). Blood pressure (BP), total cholesterol (TC), LDL cholesterol, triglyceride (TG), fasting blood glucose (FBG), HbA1c, fasting insulin (FI), insulin resistance (IR), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma glut-amyl transpeptidase (GGT), uric acid (UA), urea, creatinine, thyroid-stimulating hormone (TSH), sodium, potassium, 25-OH-Cholecalciferol Vitamin D, ferritin and CRP, were measured in 240 healthy individuals (120 males & 120 females), aged 18-60 years, grouped according to BMI into 3 main groups (overweight, obese, morbidly obese) and control (normal weight) of matched age and sex, each group divided into 3 sub-groups according to age (<20, 20-44 & ≥45 year). Significance difference between each group and control was assessed by Student t-test and association between ferritin, CRP and HOMA-IR in different BMI was measured by Pearson’s correlation analysis. P-value ≤0.05 was considered statistically significant. This study revealed a strong ascending association between obesity and BP in both sexes at different age. Both obesity across all age subgroups & morbid obesity at age <45 year were found to put individuals at prehypertension zone. However, overweight at <45 year and morbid obesity at ≥45 year resulted in incidence of hypertension. Overweight (BMI 25-29.9 kg/m²) resulted in significant higher levels of TC, LDL, TSH, ALT and ALP in young females (<20 years) and GGT, UA, vit D, and ALT in males 20-44 year, FI and HOMA-IR in both sexes at age ≥45 years and it put females ≥45 years at increased risk for future diabetes. Obesity (BMI 30-39.9 kg/m²) resulted in significant increase in LDL, FBG, TSH, ALP and GGT in young females (<20 years), ferritin, FI and IR in males <45 years, ALT, TG and UA in both sexes across all age sub-groups. It also resulted in incidence of hyperinsulinemia in young males (<20 year) and iron overload in males 20-44 year and let females ≥45 year to have borderline high lipids (TC and LDL). Furthermore, obesity put both gender ≥45 year at increased risk for future diabetes. Morbid obesity (BMI>40 kg/m²) found to significantly increase TG, FI, IR, ALT, ALP, GGT, TSH, UA in both sexes across all age sub-groups. It leaded to hyperinsulinemia in both sexes in all age sub-groups, hyperuricemia in females ≥45 year and males of all age subgroups and put males ≥45 year at borderline high TC. Morbid obesity also resulted in increased risk of diabetes in both sexes at ≥45 year and in females 20-44 year. Age and sex difference with regard to effect of obesity degree on biochemical parameters is confirmed. Significant positive correlation was found between SF and CRP across different BMI. SF level was positively correlated with IR in obese and morbidly obese, but not in overweight group.