Diabetes mellitus and raised serum triglyceride concentration in treated hypertension—are they of prognostic importance? Observational study

Objective : To analyse whether metabolic changes during long term treatment with antihypertensive drugs are associated with an increased risk of coronary heart disease. Design : Observational study. Setting : Gothenburg, Sweden. Subjects : 686 middle aged hypertensive men, recruited after screening of a random population sample, and followed for 15 years during treatment with predominantly β adrenoceptor blockers or thiazide diuretics, or both. Coronary heart disease and diabetes mellitus were registered at yearly patient examinations. Entry characteristics, as well as within study serum concentrations of cholesterol and triglycerides and the development of diabetes mellitus, were related to the incidence of coronary heart disease in a time dependent Cox's regression analysis. Main outcome variable : Coronary heart disease morbidity. Results : Diabetes mellitus, raised serum cholesterol and triglyceride concentrations present at the beginning of the study were all significantly predictive of coronary heart disease in univariate analysis. The relative risk of diabetes mellitus and of a 1 mmol/l increase in the cholesterol and triglyceride concentrations was 2.12 (95% confidence interval 1.11 to 4.07), 1.21 (1.05 to 1.39), and 1.21 (1.03 to 1.43) respectively. However, when the within study metabolic variables were analysed, only the serum cholesterol concentration was significantly and independently associated with coronary heart disease (relative risk 1.07 (1.02 to 1.13)). Although the triglyceride concentrations increased slightly during the follow up, the within study serum triglyceride concentrations were not associated with the incidence of coronary heart disease (1.04 (0.96 to 1.10)). New diabetes mellitus—that is, onset during follow up—was not significantly associated with an increased risk for coronary heart disease (1.48 (0.37 to 6.00)). Conclusions : Metabolic disturbances such as diabetes mellitus and hyperlipidaemia presenting before the start of antihypertensive treatment have a prognostic impact in middle aged, treated hypertensive men. Moreover, while within study cholesterol concentration was an independent predictor of coronary heart disease, drug related diabetes mellitus and raised serum triglyceride concentrations that are associated with treatment do not seem to have any major impact on the coronary heart disease prognosis in this category of patients. Key messages The issue of “newer” versus “older” antihypertensive agents is an important one in the treatment of hypertension This study shows that diabetes mellitus and raised serum triglyceride concentrations occurring during long term treatment of middle aged hypertensive men taking β blockers or thiazide diuretics, or both, have no major impact on the prognosis for coronary heart disease Until the outcome of controlled trials comparing “metabolically neutral” drugs with β blockers and thiazide diuretics, β blockers or thiazide diuretics, either alone or combined, should continue to be used as major first line drugs in the treatment of hypertension