A comparative study of lipid profile and autonomic functions in vegetarian and non-vegetarian postmenopausal women

Background: The prevalence of dyslipedaemia, autonomic dysfunction leading to cardiovascular diseases, increases with menopause and an ageing population. Autonomic dysfunction as measured by lower heart rate variability is an established risk factor for cardiac death. Diet and nutrition have been extensively investigated as risk factors for major cardiovascular diseases and are also linked to other cardiovascular risk factors. Objectives: To compare lipid profile and autonomic functions of postmenopausal women on vegetarian and non- vegetarian diet. Materials and Methods: 120 Postmenopausal women (menopausal duration and age-matched) without any gross systemic disease from an Industrial population were selected. Sixty women were on vegetarian diet and 60 on non-vegetarian diet. BMI and waist/hip ratios were calculated, lipid profile was analyzed, and autonomic function tests were carried out. A comparison was done between the two groups using Students t test. Pearson′s correlation coefficient was calculated between the independent variable (lipid profile parameters) and the dependent variables (deep breath test, valsalva ratio, 30:15 ratio, OTT, IHG, CPT) to understand the effect of lipid profile on autonomic control of heart. Results : Significant increases in total cholesterol, triglyceride, LDL, cholesterol/HDL ratio were noticed in women on non-vegetarian diet. Results of autonomic function tests, i.e. valsalva ratio, deep breath test, 30: 15R-R intervals ratio, isometric hand grip test, cold pressor test, and orthostatic tolerance test were significantly worsened in postmenopausal women on non-vegetarian diet. Conclusion: Dietary factors may be an important cause of alteration of lipid metabolism. Increased cholesterol decreases heart rate variability and increased LDL cholesterol decreases baroreceptor sensitivity thereby worsening autonomic functions in postmenopausal women