PRISm common among Japan’s elderly, impacts physical function

Preserved ratio impaired spirometry (PRISm) is highly common among Japan’s elderly adults, exceeding the prevalence of obstructive lung disease, and could lead to reduced respiratory and physical function, a recent study has found.

The cross-sectional analysis included 688 older adults (mean age 72.8±5.6 years, 23.5 percent men) who were screened for PRISm defined as: post-bronchodilator forced expiratory volume in the first second (FEV1) <80 percent of the predicted FEV1 and ratio of FEV1 to forced vital capacity (FVC) ≥70 percent. Physical function outcomes included grip, knee extension, and core strength, gait speed, and one-leg stance test.

Eighty participants were diagnosed with PRISm, yielding a prevalence rate of 12.0 percent. PRISm patients had similar baseline sociodemographic factors as their counterparts with normal spirometry. On the other hand, FVC (1.93±0.56 vs 2.43±0.66 L; p<0.001) and FEV1 (1.50±0.42 vs 1.94±0.53 L; p<0.001) were significantly lower in PRISm participants, as were their corresponding percentages.

In turn, the FEV1-to-FVC ratio was likewise significantly lower in patients with PRISm (78.3±6.1 percent vs 80.1±4.9 percent; p=0.041).

PRISm also significantly affected physical function, correlating with significantly worse core strength, as measured by the sit-up test (6.7±5.8 vs 8.7±6.0; p=0.032). On the other hand, patients with PRISm had significantly better one-leg stance test results (52.4±41.1 vs 36.4±34.1 seconds; p=0.008).

“As expected, our findings confirmed that restrictive ventilatory defect is a major issue. Our findings may facilitate health promotion planning and clinical goal setting, and serve to reinforce the importance of spirometry,” the researchers said.