Having either controlled and uncontrolled hypertension in patients with obesity are both linked to an increased risk of all-cause mortality
The presence of hypertension irrespective or whether or not it is controlled, in patients with obesity, increases the risk of all-cause mortality according to a large, population study by Singaporean and Australian researchers.
Hypertension is the leading cause of global cardiovascular disease and premature death with the World Health Organisation estimating that 1.28 billion adults aged between 30 and 79 have hypertension, two-thirds of whom, live in low and middle-income countries. It has also become clear that as body mass index increases, so too does the risk of hypertension. Although the prevalence of hypertension among those with obesity has been found to be above 70%, much less is known about the impact on mortality of having hypertension and whether the level of control exerts a mitigating effect.
In the current study, researchers collected data on obese patients, which was defined as adults with a body mass index (BMI) of ≥ 30.0 kg/m2. Furthermore, individuals were then stratified by their hypertensive status as either having controlled hypertension (CH) (< 140/90 mmHg) with antihypertensive use, uncontrolled hypertension (UCH) ( ≥ 140/90 mmHg) with and without antihypertensive use or normotensive. The main outcome measure was all-cause mortality.
Controlled and uncontrolled hypertension and all-cause mortality
A total of 16,386 individuals with obesity were included and of whom, just over half (53.1%) were normotensive, a quarter (24.7%) had CH with the remainder having uncontrolled disease. These individuals were then followed-up for a median of 7.3 years.
The presence of hypertension per se increased the risk of all-cause mortality (Hazard Ratio, HR = 1.28, 95% CI 1.14 – 1.44, p < 0.001). After adjustment for potential confounders, the researchers found that among obese patients with UCH, there was an increased all-cause mortality risk (HR = 1.34, 95% CI 1.13 – 1.59, p = 0.001), compared to normotensive individuals. However, there was also a significantly increased mortality risk for those with CH (HR = 1.21, 95% CI 1.10 – 1.34, p < 0.001). In fact, further adjustment of the regression model for chronic kidney disease, still gave rise to a significant risk of all-cause mortality in those with CH (HR = 1.17, p = 0.007).
The authors concluded that the excess mortality risk among obese patients, irrespective of whether their hypertension was controlled, should urge health care providers to optimise disease control and advocate weight loss to achieve better outcomes in obesity.
Kong G et al. A two-decade population-based study on the effect of hypertension in the general population with obesity in the United States. Obesity (Silver Spring) 2023