Factors predicting the development of metabolic syndrome and type II diabetes against a background of hypertension.

BACKGROUND

The metabolic syndrome (MetS), predicting coronary heart disease (CHD), is a compound of risk factors including diabetes, obesity and hypertension. The relationship between the development of MetS, diabetes and CHD in patients with established hypertension is unclear. We hypothesized that patients with hypertension developing MetS are at increased risk of type II diabetes and CHD compared with patients who do not develop MetS.

MATERIALS AND METHODS

We prospectively studied 284 patients (100 with existing/established MetS) with hypertension but without diabetes and CHD over 4 years. MetS and diabetes were diagnosed by the modified NCEP and ADA criteria, and CHD risk by the Framingham risk equation; all patients had annual fasting blood sampling.

RESULTS

Over 4 years of follow up, 75 of the 184 patients (41%) initially free of MetS at baseline subsequently fulfilled the criteria for MetS. These patients (i.e. 'developing MetS') had higher baseline BMI, triglycerides and lower HDL cholesterol, with a higher calculated CHD risk (all P <or= 0.001) than those who did not develop MetS. The 4-year odds ratios of developing diabetes in the patients with established MetS (23%) and the patients developing MetS (13.3%) vs. the patients not developing MetS (3.7%, P < 0.001) were 7.8 (95% CI: 2.6-23.5) and 4.0 (95% CI: 1.2-13.4), respectively.

CONCLUSIONS

Patients with hypertension developing MetS have an increased CHD risk and risk of developing type II diabetes even before fulfilling the criteria for MetS, and the former is comparable to patients with established MetS. These data suggest a high-risk phase not adequately identified by current diagnostic thresholds for MetS.