The prevalence of masked hypertension and masked uncontrolled hypertension in relation to overweight and obesity in a nationwide registry in China

Masked hypertension is difficult to identify and is associated with adverse outcomes. How and to what extent masked hypertension is related to overweight and obesity remain unclear. In participants with a clinic blood pressure (BP) < 140/90 mmHg enrolled in a nationwide prospective registry in China, we performed ambulatory and home BP measurements and defined masked hypertension and masked uncontrolled hypertension as an elevated 24-h (≥130/80 mmHg), daytime (≥135/85 mmHg) or nighttime ambulatory BP (≥120/70 mmHg) or an elevated home BP (≥135/85 mmHg). Overweight and obesity were defined as a body mass index of 25.0–29.9 and ≥30.0 kg/m2, respectively. The 2838 participants had a mean (±SD) age of 54.9 ± 13.6 years and included 1286 (45.3%) men and 1065 (37.5%) and 173 (6.1%) patients with overweight and obesity, respectively. Multiple stepwise regression analyses identified that body mass index was significantly (P ≤ 0.006) associated with the prevalence of masked ambulatory and home hypertension in treated (n = 1694, 58.6% and 42.1%, respectively) but not untreated participants (n = 1144, 55.7% and 29.5%, respectively). In categorical analyses, significant associations were observed with overweight and obesity for the prevalence of masked uncontrolled ambulatory and home hypertension (P ≤ 0.02) but not masked ambulatory or home hypertension (P ≥ 0.08). The adjusted odds ratios (95% confidence intervals) for overweight and obesity relative to normal weight were 1.56 (1.27–1.92) and 1.34 (1.09–1.65) for masked uncontrolled ambulatory and home hypertension, respectively. In conclusion, overweight and obesity were associated with a higher prevalence of masked uncontrolled hypertension, indicating that clinic BP might overestimate antihypertensive treatment effects in patients with overweight and obesity.