Effect of intensive and standard blood pressure control on cardiovascular outcomes based on body mass index: sub-analysis of the sprint trial

BMI and blood pressure control among United States adults with hypertension

OBJECTIVES

Less than half of United States adults with hypertension have controlled blood pressure (BP). Higher BMI is associated with an increased risk for hypertension but the association between BMI and BP control is not well characterized. We examined hypertension awareness, antihypertensive medication use, and BP control, by BMI category.

METHODS

Data for 3568 United States adults aged at least 18 years with hypertension (BP at least 140/90 mmHg or taking antihypertensive medication) from the 2015 to 2018 National Health and Nutrition Examination Survey were analyzed. BMI was categorized as normal (<25 kg/m2), overweight (25 to <30 kg/m2), class 1 obesity (30 to <35 kg/m2), or class 2 or 3 obesity (≥35 kg/m2). Hypertension awareness and antihypertensive medication use were self-reported. BP control was defined as BP less than 140/90 mmHg using the average of up to three measurements.

RESULTS

Among United States adults with hypertension, 15.6% had normal BMI, 31.3% had overweight, 26.2% had class 1 obesity, and 26.8% had class 2 or 3 obesity. Among those with normal BMI, overweight, class 1 obesity, and class 2 or 3 obesity: 67.9, 76.8, 84.0, and 87.8% were aware they had hypertension, respectively; 88.1, 88.1, 90.9, and 90.2% of those aware were taking antihypertensive medication, respectively; 63.5, 65.9, 71.1, and 64.1% of those taking antihypertensive medication had controlled BP, respectively; and 37.1, 44.3, 53.8, and 50.8% of those with hypertension had controlled BP, respectively.

CONCLUSION

United States adults with hypertension and normal BMI were less likely to be aware they had hypertension and have controlled BP compared with those with overweight or obesity.

Modification of the effects of intensive systolic blood pressure control on kidney outcomes by baseline body mass index

AIM

Obesity and intensive systolic blood pressure (SBP) control are independently associated with greater risk of acute kidney injury (AKI) and incident chronic kidney disease (CKD). We examined whether baseline body mass index (BMI) modifies the effects of intensive SBP lowering on AKI or incident CKD.

METHODS

The systolic blood pressure intervention trial (SPRINT) randomized 9361 participants with high blood pressure to an SBP target of either <120 mm Hg or < 140 mm Hg. In a secondary analysis of 9210 SPRINT participants with a baseline BMI of ≥18.5 and < 50 kg/m² , we examined the interactions of baseline BMI and SPRINT SBP intervention on subsequent AKI and incident CKD.

RESULTS

Each 5 kg/m² increase in baseline BMI was associated with higher risk of AKI (hazard ratio [HR] 1.12, 95% confidence interval [CI] 1.01 to 1.25) and incident CKD (HR 1.17, 95% CI 1.01 to 1.32). Intensive SBP control increased the risk of AKI (HR 1.68, 95% CI 1.22-2.11) and incident CKD (HR 3.49, 95% CI 2.47-4.94). The increased risk of AKI with intensive SBP control was consistent across the baseline BMI spectrum (linear interaction p = 0.55); however, the risk of incident CKD with SPRINT intervention increased with higher BMI (linear interaction p = 0.043).

CONCLUSION

The increased risk of adverse kidney events seen with intensive SBP control in the SPRINT persisted across the baseline BMI spectrum. A higher baseline BMI was associated with an augmented risk of incident CKD with intensive SBP control.