SETTING Factors that influence the annual rate of decline of lung function need to be verified.

OBJECTIVE To determine the effects of metabolic syndrome, especially hypertension, on the annual rate of decline in lung function.

DESIGN A total of 635 healthy participants without known respiratory disease completed baseline and follow-up routine check-ups, including a pulmonary function test, for at least 3 years. Age, sex, height, weight, waist circumference, smoking status, other underlying diseases, and pulmonary function and blood test results were carefully reviewed.

RESULTS In a multivariable analysis of baseline data, diabetes was associated with lower forced vital capacity (FVC). In longitudinal analysis using mixed linear regression, hypertension was an independent predictor for acceleration of FVC decline rate compared to subjects without hypertension (-37.2 vs. -18.5 ml/year), while anti-hypertensive medication decelerated FVC decline in hypertensive subjects (-58.9 vs. -32.3 ml/year). The annual rate of decline in forced expiratory volume in 1 second (FEV1) in groups with and without hypertension did not differ significantly. No significant difference was found in FEV1 or FVC annual rates of decline with regard to the presence of diabetes, dyslipidaemia, obesity or abdominal obesity.

CONCLUSION Hypertension is associated with an accelerated decline in FVC, but anti-hypertensive medication might abate the rate of decline in asymptomatic healthy subjects.