78 * IS GRIP STRENGTH ASSOCIATED WITH LUNG FUNCTION IN OLDER HOSPITALISED PATIENTS?

Abstract

Introduction: Age-related airway compliance changes contribute to the declining ratio of forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) with ageing. This leads to increased airflow obstruction during forced expiration. Consequently, many older people meet the spirometric criteria for obstructive airways disease despite no other evidence. Older people may be unable to generate and sustain sufficient expiratory pressure to reach and hold maximum flow as lung volume falls. This study used grip strength (GS) to reflect expiratory muscle strength (EMS) in investigating the relationship between EMS and lung function (LF). Methods: Patients on acute Medicine for Older People wards were recruited who met the inclusion criteria: age above 70 years; never smoked; no history, symptoms or signs of respiratory disease; Mini Mental State Examination (MMSE) ≥24; willing and able to consent to participate; able to perform hand grip and forced spirometry. Outcome measure was LF (FEV1, FVC, FEV1/FVC, peak expiratory flow rate (PEFR) and slow vital capacity (SVC)), covariates were GS, age, weight, height. Unadjusted and adjusted (for age, height, weight) linear regressions were used for analysis. Results: 50 patients (male = 20, female = 30) were recruited. Significant relationships were found in men between GS and FEV1 (unadjusted β = 0.032, 95%CI = (0.001,0.063), p = 0.047) although not significant after adjustment; in women between GS and PEFR (unadjusted β = 6.881, 95%CI = 1.537,12.226, p = 0.013); (adjusted β = 6.938, 95%CI = 1.268,12.607, p = 0.018), and in women between GS and SVC (unadjusted β = 0.052, 95%CI = 0.006,0.099, p = 0.028); (adjusted β = 0.050, 95%CI = 0.0005,0.100, p = 0.048). No other significant relationship was found. Conclusions: The relationship of GS with PEFR and SVC in women might reflect stronger patients generating higher intra-thoracic pressure at the start of spirometry and pushing harder against thoracic cage recoil at end-expiration. No significant relationship was found with FEV1/FVC and GS in this small study. Further research is needed to evaluate the relationship between LF and GS.