Hypertension in diabetes: is there a place for age-adjusted centile cut-offs in those aged <50 years?

• Published in: QJM : An International Journal of Medicine Vol. 97; no. 11; pp. 747 - 753
• Main Authors: Baskar, V., Kamalakannan, D., Holland, M.R., Singh, B.M.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01-11-2004; Oxford Publishing Limited (England)
• Subjects: Adolescent; Adult; Age Distribution; Aged; Aging - physiology; Biological and medical sciences; Blood Pressure - physiology; Diabetes Complications - diagnosis; Diabetes Complications - epidemiology; Diabetes Complications - physiopathology; England - epidemiology; Female; General aspects; Humans; Hypertension - diagnosis; Hypertension - epidemiology; Hypertension - physiopathology; Male; Medical sciences; Middle Aged; Prevalence; Reference Values; Sex Distribution; England; Endocrinopathy; Human; Hypertension; Medicine; Diabetes mellitus; Cardiovascular disease; Elderly; Age
• ISSN: 1460-2725; 1460-2393
• DOI: 10.1093/qjmed/hch123

Background: Conventional cut-offs for hypertension are arbitrary, and vascular complications can occur below these values, particularly in diabetes. Aim: To evaluate systolic blood pressure (SBP) distribution in diabetes and control populations, comparing hypertension prevalence using either conventional cut-offs (140 and 160 mmHg) or age-adjusted centile (75th and 90th) cut-offs derived from the control population. Methods: We compared 2521 individuals with diabetes to 5809 controls, after excluding those on anti-hypertensives and with established vascular disease in both groups. Results: Diabetic individuals were older (mean ± SD 56 ± 16 vs. 43 ± 16years, diabetes vs. controls), and had higher BMI (29 ± 5 vs. 24 ± 4 kg /cm2) and SBP (145 ± 23 vs. 131 ± 18 mmHg, all p < 0.001). These factors were adjusted for in subsequent analysis. SBP rose with age and was also significantly higher in the diabetes group. In diabetes, conventional cut-offs indicated less hypertension in those aged < 50 years, compared to age-adjusted centile cut-offs. In age bands 18–29, 30–39, 40–49, 50–59, 60–69 and >70 years of the diabetes group, 24%, 33%, 43%, 62%, 70% and 74%, respectively exceeded 140 mmHg, compared to 35%, 44%, 43%, 45%, 40% and 27% exceeding the control-derived 75th centile value. Discussion: The use of control-derived age-adjusted cut-offs may provide an alternative approach to define hypertension in diabetes that may be of particular relevance to younger patients, although this would require validation against outcomes.