Author(s): Trinath Kumar Mishra1, Biswajit Das2, Nirmal Kumar Mohanty3
INTRODUCTION: Globally type 2 diabetes is in increasing trend with projected 366 million by 2030. The number of adults with hypertension is predicted to increase by 60% to a total of 1.56 billion people by 2025. 70% patients with DM have hypertension and hypertension is approximately twice as common in persons with diabetes as in those without. In the Hong Kong Cardiovascular Risk Factor Prevalence Study, 58% of people with diabetes had HTN and 44% of people with hypertension had dysglycemia.
Diabetes and hypertension constitute the Siamese twin in the tragic story cardiovascular forum. In type 2 DM, HTN dictates the story of metabolic syndrome where as in type 1 it fingers at the onset of nephropathy. Hypertension increases the risk of DM and vice versa explaining the symbiotic lethal chemistry between two. Hypertension substantially increases the risk of both macro vascular and micro vascular complications, including stroke, coronary artery disease, peripheral vascular disease, retinopathy, nephropathy, and possibly neuropathy in diabetes mellitus.
Coexistence of hypertension and diabetes can pose serious risks in subpopulations like pregnant women being at risk for pre-eclampsia and children being particularly vulnerable to end-organ disease and accelerated atherosclerosis with aging. Diabetes carries 2 fold risk of CVD in men and four fold risk of CVD in post-menopausals. Diabetes and HTN in combination has 2 fold more CVD than hypertension alone. They potentiate the complication of each other. In UKPDS study 10 mmHg decrease in SBP decreased any complication by 12%, mortality by 13%, MI by 11% and micro vascular complication by 13%.
PATHOPHYSIOLOGY: As the disease progress the diabetics acquire HTN, dyslipidemia, atherosclerosis and CVD. Obesity, inflammation, oxidative stress and insulin resistance are the common to the duos.DM and HTN share common pathways of SNS, RAAS, oxidative stress, adipokines, insulin resistance, PPARs and both cause a vicious cycle. They may, therefore, develop one after the other in the same individual.
Physical activity plays an important protective role in both of them. Both share the common genetic or environmental factors as evidenced in Hong Kong and Columbia studies of single nucleotide polymorphisms (SNPs), SNPs that predict the development of diabetes were also found also to predict the development of hypertension.