Evidence that prehypertension is a risk factor for Type 2 diabetes

Pre-hypertension and the risk of diabetes mellitus incidence using a marginal structural model in an Iranian prospective cohort study

OBJECTIVES

The aim of this study was to evaluate the effect of pre-hypertension and its sub-classification on the development of diabetes.

METHODS

In this cohort study, 2,941 people 40 to 64 years old without hypertension or diabetes were followed from 2009 through 2014. According to the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC)-7 criteria, we classified participants into normal and pre-hypertension groups. The effect of pre-hypertension on the 5-year incidence rate of diabetes was studied using inverse probability of treatment weighting. We modeled the exposure and censored cases given confounding factors such as age, sex, body mass index, smoking, economic status, and education.

RESULTS

The 5-year incidence rate of diabetes among people with pre-hypertension and those with normal blood pressure (BP) was 12.7 and 9.7%, respectively. The risk ratio (RR) for people with pre-hypertension was estimated to be 1.13 (95% confidence interval [CI], 0.90 to 1.41). The RRs among people with normal BP and high-normal BP, according to the JNC-6 criteria, compared to those with optimal BP were 0.96 (95% CI, 0.73 to 1.25) and 1.31 (95% CI, 1.01 to 1.72), respectively.

CONCLUSIONS

Our results showed that participants who had higher levels of BP (high-normal compared to optimal BP) had a higher risk of diabetes development. With regard to the quantitative nature of BP, using the specifically distinguishing of stage 1 hypertension or high-normal BP may be a more meaningful categorization for diabetes risk assessment than the JNC-7 classification.

Hypertension is an independent risk factor for type 2 diabetes: the Korean genome and epidemiology study

Hypertension and diabetes share common risk factors and frequently co-occur. Although high blood pressure (BP) was reported as a significant predictor of type 2 diabetes, little is known about this association in Korea. This study investigated the relationship of prehypertension and hypertension with type 2 diabetes in 7150 middle-aged Koreans, as well as the effect of BP control on diabetes development over 8 years. At 8 years, 1049 (14.7%) of the 7150 participants had newly developed diabetes, including 11.2, 16.7 and 21.5% of baseline normotensive, prehypertensive and hypertensive subjects, respectively. The overall incidence rate of diabetes was 22.3 events per 1000 person-years. Subjects with baseline prehypertension (hazard ratio (HR), 1.27; 95% confidence interval (CI), 1.09-1.48) and hypertension (HR 1.51; 95% CI, 1.29-1.76) were at higher risk of diabetes than normotensive subjects after controlling for potential confounders (P-value for trend <0.001). These associations persisted even when subjects were stratified by baseline glucose status, sex and body mass index (BMI). The risk of diabetes was significantly higher in subjects who had normal BP at baseline and progressed to prehypertention or hypertension at 8 years (HR, 1.48; 95% CI, 1.20-1.83) than those with controlled BP, but these associations were not observed in subjects with baseline prehypertension and hypertension. These findings showed that prehypertension and hypertension are significantly associated with the development of diabetes, independent of baseline glucose status, sex and BMI. Active BP control reduced incident diabetes only in normotensive individuals, suggesting the need for early BP management.

Sex-specific predictors of the prehypertension-to-hypertension progression: community-based cohort of a West-Asian population

BACKGROUND

We aimed to predict prehypertension-to-hypertension progression rate among a West-Asian adult population.

METHODS

We analyzed data on 3449 adults (mean age 41.0 years), prehypertensive at baseline, attending at least one follow-up visit, contributing 25,079 person-years follow-up. A proportional hazard regression analysis was implemented to model the interval-censored progression-free survival time data using readily-assessable, commonly-available information. Integrated discriminatory improvement (IDI) and net reclassification improvement (NRI) indices were calculated to examine whether simple clinical information could help improve prediction of prehypertension-to-hypertension progression rate based on the blood pressure measures.

RESULTS

During a median seven-year follow-up 1412 prehypertensive patients progressed to hypertension with annual progression rate (95% confidence intervals (CIs)) being 56.9 (52.9-61.2) per 1000 women and 55.7 (51.7-60.0) per 1000 men (p = 0.007). High-density lipoprotein cholesterol levels were inversely associated with prehypertension-to-hypertension progression rate only among women (hazard ratio (1-SD): 0.93, 95% CIs: 0.86-0.100). Marital status retained its predictability among women even after multivariate adjustments. In both men and women, age, blood pressure measures, waist-to-height ratio, fasting plasma glucose and a history of cardiovascular disease independently predicted prehypertension-to-hypertension rate. The absolute (0.114, 95% CIs: 0.107-0.120) and relative (2.638, 95% CIs: 2.374-2.903) IDI and cutpoint-based (0.213, 95% CIs: 0.156-0.269) and cutpoint-free NRI (0.523, 95% CIs: 0.455-0.591) indicated that the prediction of the prehypertension-to-hypertension progression was improved by multivariable-models compared with blood pressure measures alone.

DISCUSSION

Easily-assessable, commonly-available information helped improve predictability of blood pressure measures for prehypertension-to-hypertension progression. Women's psycho-social characteristics (marital status) should be considered in prevention of prehypertension-to-hypertension progression.

Prehypertension in a Mexican population: influence of age, gender, and body fat

We studied the association of age, gender, and distribution of body fat with prehypertension in a sample of Mexican adults. This study was performed in a sample of 900 adults (275 men and 625 women), with the median age of 42 years. Resting blood pressure was measured in duplicate, and prehypertension and hypertension were defined according to JNC 7 criteria. The prevalence of hypertension and prehypertension in our population was 11.56% and 26.5%, respectively. The prevalence of prehypertension was significantly higher in men than in women. Prehypertension was associated with middle and old age (odds ratio [OR] = 2.6 and 2.4, respectively, P < .001), abdominal obesity (OR = 1.3, P = .008), upper quintiles of body mass index (OR = 2.05, P = .005), waist (OR = 1.97, P = .01) and hip (OR = 2.04, P = .005) circumferences, and body fat (OR = 2.37, P = .001). The main factors associated with the development of prehypertension are age, central obesity, and body fat.