The aim of the study was to compare the predictive role of isolated systolic hypertension (ISH) and combined systolic-diastolic hypertension for the incidence of new-onset diabetes mellitus (NOD) in essential hypertensive patients.
We followed up 1435 non-diabetic essential hypertensives with office systolic blood pressure (BP)>or = 140 mmHg [mean age 57 years, 730 males, office BP = 153/92 mmHg] for a mean period of 8 years. All subjects had at least one annual visit and at baseline underwent echocardiographic study and blood sampling for estimation of metabolic profile. Patients with baseline ISH exhibited office systolic BP >or = 140 mmHg and office diastolic BP < 90 mmHg, while those with systolic-diastolic hypertension had office systolic BP >or = 140 mmHg and office diastolic BP >or = 90 mmHg. Moreover, NOD was defined if at one or more of the follow-up visits a previously non-diabetic patient reported being on insulin or an oral hypoglycemic drug or if casual plasma glucose concentration >or = 200 mg/dl or fasting glucose concentration >or = 126 mg/dl or 2-h post load glucose >or = 200 mg/dl during an oral glucose tolerance test.
The incidence of NOD over the follow-up period was 4.2% (n = 60). Patients with ISH (n = 460) compared to those with systolic-diastolic hypertension (n = 975) were older (65 ± 11 vs 54 ± 10 years, p < 0.0001), had at baseline lower waist circumference (94.5 ± 11 vs 99 ± 13 cm, p < 0.0001), office systolic BP (149 ± 12 vs 155 ± 13 mmHg, p < 0.0001), office diastolic BP (80 ± 8 vs 98 ± 6 mmHg, p < 0.0001), while did not differ regarding left ventricular mass index, glucose and lipid levels (p = NS for all). Univariate Cox regression analysis revealed that baseline ISH (hazard ratio = 2.143, p = 0.016) and systolic-diastolic hypertension (hazard ratio = 1.272, p = 0.029) predicted NOD. However, in multivariate Cox regression model, age (hazard ratio = 1.039, p < 0.001), baseline glucose levels (hazard ratio 1.011, p = 0.016), waist circumference (hazard ratio=1.067, p < 0.001) and ISH (hazard ratio=1.651, p = 0.029) but not systolic-diastolic hypertension were be independent predictors of NOD.
ISH but not systolic-diastolic hypertension exhibits independent prognostic value for NOD. These findings support that ISH constitutes a hypertensive phenotype of increased metabolic risk needing careful evaluation and treatment.
First Cardiology Clinic, Medical School, National and Kapodistrian University of Athens, Hippokration Hospital, Athens, Greece