White-coat and masked hypertension are associated with albuminuria in a general population: The Hisayama Study

Epidemiological and clinical studies have investigated the influence of hypertension on chronic kidney disease (CKD), but limited data are available for the associations of white-coat hypertension (WCHT), masked hypertension (MHT) and sustained hypertension (SHT) with kidney dysfunction in general populations. We examined the associations of these types of hypertension with CKD (albuminuria and reduction in estimated glomerular filtration rate (eGFR)) in a cross-sectional survey of 2974 community-dwelling Japanese aged ≥40 years. The types of hypertension were defined based on combined measurements of clinic and home blood pressures. Albuminuria was determined as urinary albumin-creatinine ratio (UACR) levels ≥30.0 mg g^-1. The eGFR was calculated using the Japanese equation. The age- and sex-adjusted geometric mean of the UACR values was significantly higher in the subjects with WCHT (20.2 mg g^-1), MHT (19.6 mg g^-1) and SHT (31.6 mg g^-1) than in those with normotension (NT) (12.5 mg g^-1) (all P<0.001). Compared with NT, all types of hypertension were significantly associated with an increased likelihood of albuminuria (the age- and sex-adjusted prevalence of albuminuria; NT 14.1%, WCHT 26.3%, MHT 26.4% and SHT 43.3%; all P<0.001). These associations remained significant even after adjustment for other risk factors. However, the age- and sex-adjusted mean of eGFR and the prevalence of low eGFR (<60 ml min^-1 per 1.73 m2) did not differ between NT and the three hypertension types. The associations of the types of hypertension with the likelihood of CKD were similar to those for albuminuria. Our findings suggest that WCHT, MHT and SHT are associated with albuminuria in the general Japanese population.