Moderate thinness and its association with muscle strength of children 5 to 7 years in Ethiopia: a comparative cross-sectional study.

Objective: This study aimed to investigate the association between moderate thinness (MT) and muscle strength among children aged 5-7 years old in Ethiopia.

Design: A school-based comparative cross-sectional study was conducted between June to July 2022. Their nutritional status (MT versus well-nourished (WN) was identified using BMI-for-age-and-sex; hand grip was measured using a digital grip strength dynamometer, and biceps, quadriceps, and gastrocnemius strength were measured with Digital (Handheld) Dynamometry. Independent predictors of muscle strength were identified using a multivariable linear regression model.

Setting: The study was conducted in Kindergarten and primary schools of Jimma Town, located in Southwest Ethiopia.

Participants: Children 5-7 years old (n=388) with moderate thinness (MT=194) and well-nourished peers (WN=194).

Results: Children with MT (n=198) had significantly lower grip strength, biceps, quadriceps, and gastrocnemius muscle groups than WN children (n=198) (p< 0.001). The mean and standard deviation of grip strength were 4.15 ± (2.56) kilograms (kg) for MT and 5.6 ± (2.04) kg for WN children. Biceps strength was 34.3 ± (7.34) Newton (N) for MT and 48 (11.69) N for WN children. Gastrocnemius strength was 30.1 (6.9) N for MT and 45.1 ± (9.7) N for WN children. After adjusting for background characteristics, WN children had 1.38 times higher grip strength (β=1.38, p <0.001), 11.22 times higher biceps strength (β=11.22, p<0.001), 16.70 times higher quadriceps strength (β=16.70, p<0.001), and 12.75 times higher gastrocnemius strength (β=12.75, p<0.001) than MT children.

Conclusion: Children with MT had significantly lower muscle strength than their WN counterparts. This highlights the negative functional effect of wasting.