Criterion-Referenced Standards of Handgrip Strength for Identifying the Presence of Hypertension in Croatian Older Adults

Background: It is well known that muscular fitness has been associated with hypertension. However, it is less known which cut-off values of muscular fitness may predict the presence of hypertension. The main purpose of this study was to establish criterion-referenced standards of muscular fitness to define the presence of hypertension in Croatian older adults. Methods: In this cross-sectional study, we recruited men and women over 60 years of age. Muscular fitness was assessed by handgrip strength and normalized by height squared. Hypertension was defined as having systolic blood pressure ≥130 mm/Hg or diastolic blood pressure ≥80 mm/Hg. Results: In older men, the optimal cut-point of muscular fitness in defining hypertension was 15.4 kg/m(2). The area under the curve (AUC) was 0.85 (96% CI 0.77 to 0.92, p < 0.001). In older women, the optimal cut-point was 11.8 kg/m(2), with an AUC of 0.84 (95% CI 0.80 to 0.89, p < 0.001). Men and women with cut-points of < 15.4 kg/m(2) and < 11.8 kg/m(2) were 11.8 (OR = 11.8, 95% CI 4.3 to 32.4, p < 0.001) and 10.6 (OR = 10.6, 95% CI 5.7 to 19.7, p < 0.001) times more likely to be diagnosed with hypertension. Conclusions: Our newly developed cut-points of muscular fitness assessed by the handgrip strength and normalized by height squared have satisfactory predictive validity properties in detecting men and women aged 60-81 years with hypertension.