Relationship between blood glucose levels and muscle strength in rural South African children aged 7 to 11 years: Ellisras Longitudinal Study
The prevalence of diabetes is increasing worldwide. High blood glucose has been associated with loss of muscle strength and mass in the lower extremities. However, in African children, little is known about the association between handgrip strength, flexed arm hang or other measures of muscle strength with blood glucose. The objective of the study was to investigate the association between handgrip strength and flexed arm hang with blood glucose levels amongst Ellisras rural children aged 7 to 11 years. All 279 children (164 boys and 115 girls) from Ellisras rural areas underwent strength measurements using handgrip and flexed arm hang tests. Oral glucose tolerance test was performed to measure blood glucose levels. Pearson correlation was used to determine the correlation between handgrip, flexed arm hang and blood glucose level. Linear regression was used to test the association between blood glucose `level and handgrip amd flexed and flexed arm hang measurements. The prevalence of pre-diabetes ranged from 1.7% for girls and 1.8% for boys using post-load blood glucose levels. Left handgrip was significantly correlated (r2 =0.19) with fasting blood glucose in boys only. Furthermore, linear regression showed that there was a positive significant association between left handgrip and fasting blood glucose after adjusting for age, gender and family history of diabetes (P < 0.05; β = 0.01, 95% Cl –0.01 to 0.02). There was a significantly positive association between fasting blood glucose levels and left handgrip strength among Ellisras rural children. Further studies should examine the relationship between change in glycaemic status with grip strength and other glucose biomarkers such as glycated haemoglobin (HbA1c) over time.
Keywords: Blood glucose levels, type 2 diabetes mellitus, handgrip strength, OGTT, Ellisras rural children.