Prevalence of isolated nocturnal hypertension among patients with type 2 diabetes mellitus

Abstract

Objective: To determine the prevalence of isolated nocturnal hypertension (INH) in patients with type 2 diabetes (T2D), and secondarily, to assess its frequency in those with normal office blood pressure and not receiving antihypertensive treatment. Methods: This was a cross-sectional study including patients aged ≥18 years with T2D who underwent 24-h ambulatory blood pressure monitoring (ABPM) between January 2022 and December 2024. INH was defined as mean nocturnal BP ≥ 120/70 mmHg with normal daytime BP (<135/85 mmHg). Office BP was classified into four categories according to European guidelines. Target organ damage (TOD) was assessed in a subsample through echocardiography and urinary albumin-to-creatinine ratio. Results: A total of 439 patients were included (57.6 % women; mean age 56.5 ± 10.4 years). The prevalence of INH was 21.9 % (95 % CI 0.18-0.26). Among individuals with normal office BP and no antihypertensive treatment (n = 57), INH prevalence was 31.6 %, being the most frequent phenotype of masked hypertension. INH was associated with lower HDL-C, higher triglycerides, and greater evidence of subclinical TOD compared to normotensive patients. Conclusion: INH is highly prevalent in individuals with T2D, especially among those untreated and with normal office BP. Given its association with subclinical TOD and lack of clinical predictors, ABPM should be considered in all T2D patients regardless of office BP values.