Aging and hormonal changes in and after postmenopause are the factors which play the most important role in the development of all events of this stage of women's life . Of these is the obesity and related events as insulin resistance , oxidative stress , dyslipidemia and consequent increase in the risk of cardiovascular disease. Objectives: The present work was undertaken to evaluate the effect of obesity and
hormonal changes on the insulin resistance , leptin and oxidative stress in postmenopausal women.
Subjects and methods: Thirty seven premenopausal women (mean age of 33.95 ± 7.9 years) and forty one postmenopausal women (mean of age of 59.9 ± 7.2 years) were involved in this study. They all attended Al-Kadhimyia Teaching Hospital for different purposes during the period from August 2008 to January 2009. All were apparently normal and without a previous history of any disease or illness. Serum sampling collected from all women after 12 hours fast was separated and divided into aliquots for the measurement of lipids ( total cholesterol ,TC ; triglyceride ; TG ; low density lipoprotein cholesterol , LDL-C; & high density lipoprotein cholesterol, HDL-C ) and glucose levels by enzymatic methods . Total thiols ( t-GSH) by colorimetric method. Insulin, leptin and ox-LDL values were determined by enzyme linked immune sorbent
assay (ELISA). The sex hormone estradiol (E2) was measured the radio immuno assay (RIA), whereas the folliclular stimulating hormone (FSH) & luteinizing hormone(LH) were analyzed by immuno radiometric assay (IRMA). Vitamin E levels were quantitated by high performance liquid chromatography (HPLC). Please purchase PDPFD SFp lCit-rMeaetregde w ointh w dwewsk.vPeDryFp PdDf.cFo Wm rtiote rre -m Torivael :t:h hist twp:a//twerwmwa.rdko.cudesk.com All women were subjected to the anthropometric measurements including Body Mass Index ( BMI ) and Waist Circumference ( WC ). The index of the insulin resistance was calculated according to the QUICKI formula with a cutoff point ≤ 0.33. Results: There were significant elevation in the mean concentration of FSH, TC, LDL-c, and WC in the postmenopausal women as compared to their respective values in the premenopausal women. On the other hand, there were statistically significant decrease in the mean E2 (P ≤0.00001), HDL-c (P ≤0.0001) , and the antioxidant
weaker t-GSH (P ≤0.00001) in postmenopausal women in comparison to those of the premenopausal women. According to their BMI, both the premenopause and postmenopause women were categorized into three groups (normal < 25 Kg/m2 ,overweight 25- 29.9 Kg/m2 and obese > 30 Kg/m2 ). Between groups ANOVA test revealed :- A- In postmenopausal women of normal BMI (BMI < 25 Kg /m2 ) there were significantly higher mean values of WC (75.5±3.53 cm , P≤0.007) , Ox-LDL (61.38±16.4 U/l, P≤0.0184) , AI
(2.24±0.61,P≤0.0359) , LH (37.98±11.21 ρg/ml, P≤ 0.00001 ) and FSH (48.34±12.44 ρg/ml, P≤0.00001) as compared to those of premenopausal women with normal BMI. On the contrary, there were lower serum values of E2 (61.63±12.99 ρg/ml ,P≤0.00001) , HDL-C (51.75±5.91 mg/dl , P≤0.045) and t-GSH (0.47±0.14 mmole/l, P≤0.003). No significant difference was observed in the serum leptin , insulin or IR test results.
B-In the postmenopausal overweight women (BMI =25- 29.9), there were significant elevations in the means of WC (90.29±7.18 cm, p≤0.0013), TC (206.71±37.87mg/dl, p≤0.0312) , TG (151.64±44.28 Please purchase PDPFD SFp lCit-rMeaetregde w ointh w dwewsk.vPeDryFp PdDf.cFo Wm rtiote rre -m Torivael :t:h hist twp:a//twerwmwa.rdko.cudesk.com mg/dl ,P≤ 0.0272), AI (2.98±1.13, P≤0.006),LH and FSH
(40.11±12.21 , P≤0.00001; 56.66±12.63, P≤ 0.00001 ρg/ml, respectively) in reference to their counter parts of premenopausal overweight women .On the other hand, significant reduction was reported in the serum mean E2 (57.61±16.6 ρg/ml , P≤0.00001) , HDL-c (46.36±5.96 mg/dl, P≤0.0025), and t-GSH (0.36±0.07
mmole/l, P≤0.00001) in comparison to those of premenopause overweight females values. Yet, no differences were recorded in the mean serum levels of ox-LDL (71.09±24.71 U/l) and IR (0.35±0.04).
C-The obese postmenopausal women were having higher values of WC (100.07±8.17 cm, P≤ 0.0065), serum glucose(93.2±15.06mg/dl, P≤0.0478),TC (225.0±31.45 mg/dl, P≤0.0009), LDL-c (152.53±32.7
mg/dl , P≤0.0003), AI(3.63±1.15, P≤0.0009),ox-LDL (102.81 ± 42.96 U/l, P≤0.0435) , LH(45.85±10.83 ρg/ml, P≤0.00001)and FSH (59.83±10.69 ρg/ml, P≤0.00001). and lower concentrations of serum E2 (51.25±15.59 ρg/ml, P≤0.00001), HDL-c (43.87±6.67 mg/dl, P≤0.0477), and t-GSH (0.3±0.06 mmole/l, P≤0.0001) as compared to their respective mean values of obese premenopausal women.There was a negative correlation between serum estradiol ( E2) and each of BMI and t-GSH in the premenopausal women Whereas, the body weight parameters ( BMI & WC) were positively associated with serum leptin and ox-
LDL , and negatively correlated with QUICKI test , t- GSH , and vitamin E in both groups. The serum leptin concentration was directly correlated with ox- LDL and TG ,and inversely associated with the QUICKI test and HDL-C in both premenopausal and postmenopausal groups. Furthermore, there were significant positive relationships between the serum total thiols ( t-GSH) and vitamine E values in both groups. Please purchase PDPFD SFp lCit-rMeaetregde w ointh w dwewsk.vPeDryFp PdDf.cFo Wm rtiote rre -m Torivael :t:h hist twp:a//twerwmwa.rdko.cudesk.com Conclusion: The present data suggests that changes in serum levels of sex hormones at menopause may be the trigger for the development of postmenopausal obesity and related events as increased leptin , insulin resistance , dyslipidemia and oxidative stress ( high ox-LDL , and low antioxidants) Whereas , the age may have a permissive role in this respect. Please purchase PDPFD SFp lCit-rMeaetregde w ointh w dwewsk.vPeDryFp PdDf.cFo Wm rtiote rre -m Torivael :t:h hist twp:a//twerwmwa.rdko.cudesk.com