Impaired grip strength in children with congenital heart disease

OBJECTIVES: Grip strength is known to be reduced in adults with congenital heart disease (CHD). This study compared grip strength in paediatric patients with CHD with healthy controls and determined a possible association between grip strength and health-related physical fitness (HRPF). METHODS: Grip strength and HRPF were assessed in 569 children (12.4 years, 95% CI 12.16 to 12.72; 238 girls) with various CHD and compared with 2551 healthy controls (11.4 years, 95% CI 11.3 to 11.5; 1424 girls). Grip strength was determined as the maximum value of three repetitions with each hand. HRPF was tested by five motor tasks (FITNESSGRAM) and converted into an SD score (z-score). RESULTS: After adjusting for age, sex and weight, children with CHD showed significantly lower grip strength compared with healthy controls (CHD: 20.8 kg, 95% CI 20.4 to 21.2; controls: 24.5 kg, 95% CI 24.3 to 24.8). CHD subgroup analysis also revealed significantly lower grip strength than the controls, with the lowest values in patients with total cavopulmonary connection (19.1, 95% CI 18.0 to 20.2). Children with complex CHD showed the lowest values with 19.8 kg (95% CI 19.2 to 20.4), those with moderate 20.7 kg (95% CI 19.9 to 21.4) and those with simple 22.5 kg (95% CI 21.6 to 23.3), respectively. HRPF was also lower (z-score: -0.46, 95% CI -0.49 to -0.35) compared with healthy controls and poorly associated with grip strength (r=0.21). CONCLUSIONS: Grip strength is already reduced in children with CHD and poorly associated with HRPF. This suggests that grip strength and HRPF are different domains and have to be assessed separately.