Relationship between blood pressure and glucose tolerance in acromegaly

BACKGROUND Hypertension represents a well-known risk factor for cardiovascu lar diseases. The pathogenesis of hypertension in acromegaly is commonly vi ewed as multifactorial, but the possible influence of metabolic disorders o n blood pressure (BP) in affected patients is largely unknown. OBJECTIVE The aim of the present study was to evaluate the impact of glucos e metabolism abnormalities on BP values in a series of patients with active acromegaly. DESIGN An open multicentre prospective study. PATIENTS Sixty-eight patients with active disease, aged 47.5 +/- 11.7 years , have been studied. Thirty-nine had normal glucose tolerance (NGT), 16 imp aired glucose tolerance (IGT) and 13 suffered from diabetes mellitus (DM). MEASUREMENTS Mean clinical BP values were calculated as the mean of BP valu es obtained by sphygmomanometric measurement in three separate occasions an d mean 24-h, diurnal and nocturnal systolic (SBP) and diastolic (DBP) value s were obtained by 24-h ambulatory blood pressure monitoring (ABPM). RESULTS Patient's age and the degree of glucose tolerance abnormalities wer e found to significantly and independently influence BP values. All clinica l and ABPM SBP and DBP values significantly increased with age by linear re gression (P < 0.02 for all BP values, 0.30 less than or equal to R less tha n or equal to 0.43), and the independent influence of this parameter on BP values was confirmed by mutivariate analysis. Similarly, the independent in fluence of glucose tolerance abnormalities on BP values was confirmed when introducing age as a covariable in a multivariate analysis, and patients wi th DM presented significantly higher clinical SBP and 24-h, diurnal and noc turnal SBP and DBP than patients with NGT (P < 0.02 for clinical SBP, P < 0 .015 for all ABPM values, respectively). In addition, patients with DM show ed significantly higher 24-h, diurnal and nocturnal DBP than those with IGT (P < 0.05 in all cases). In contrast, no significant difference was found between NGT and IGT patients. No significant influence of disease duration, BMI, GH, IGF-I, or fasting and 2-h post glucose load insulinaemia on BP va lues was observed. CONCLUSIONS Abnormalities of glucose metabolism significantly contribute to increase systolic blood pressure and especially diastolic blood pressure i n acromegalic patients. Careful control of blood pressure and of risk facto rs for developing systemic hypertension, with special reference to glucose tolerance, is mandatory to decrease cardiovascular morbidity and mortality in such patients.