Low muscle strength is associated with metabolic risk factors in Colombian children: the ACFIES study

Abstract

Purpose: In youth, poor cardiorespiratory and muscular strength are associated with elevated metabolic risk factors. However, studies examining associations between strength and risk factors have been done exclusively in high income countries, and largely in Caucasian cohorts. The aim of this study was to assess these interactions in schoolchildren in Colombia, a middle income Latin American country.

Methods: We measured body mass index, body composition, handgrip strength (HG), cardiorespiratory fitness (CRF) and metabolic risk factors in 669 low-middle socioeconomic status Colombian schoolchildren (mean age 11.52±1.13, 47% female). Associations between HG, CRF and metabolic risk factors were evaluated.

Results: HG and CRF were inversely associated with blood pressure, HOMA index and a composite metabolic risk score (p<0.001 for all) and HG was also inversely associated with triglycerides and C-reactive protein (CRP) (both p<0.05). Associations between HG and risk factors were marginally weakened after adjusting for CRF, while associations between CRF and these factors were substantially weakened after adjusting for HG. Linear regression analyses showed inverse associations between HG and systolic BP (β = -0.101; p = 0.047), diastolic BP (β = -0.241; p> = 0.001), HOMA (β = -0.164; p = 0.005), triglycerides (β = -0.583; p = 0.026) and CRP (β = -0.183; p = 0.037) but not glucose (p = 0.698) or HDL cholesterol (p = 0.132). The odds ratios for having clustered risk in the weakest quartile compared with the strongest quartile were 3.0 (95% confidence interval: 1.81-4.95).

Conclusions: In Colombian schoolchildren both poorer handgrip strength/kg body mass and cardiorespiratory fitness were associated with a worse metabolic risk profile. Associations were stronger and more consistent between handgrip and risk factors than between cardiorespiratory fitness and these risk factors. Our findings indicate the addition of handgrip dynamometry to non-invasive youth health surveillance programs would improve the accuracy of the assessment of cardio-metabolic health.

Figure 1. Metabolic risk factors according to quartile of handgrip strength in 8–14 year old children (n = 536).

Quartile 4 is the highest HG category. Handgrip quartiles are age and sex specific handgrip/kg body mass. Linear trend evaluated using Kruskal–Wallis test.

Figure 2. Metabolic risk score according to quartile of handgrip strength in 8–14 year old children (n = 536).

Quartile 4 is the highest HG category. Handgrip quartiles are age and sex specific handgrip/kg body mass. Linear trend evaluated using Kruskal–Wallis test. Metabolic risk score is summed standardized residuals (z-score) by age and sex for HOMA score, waist circumference, TG, HDL-c, and systolic blood pressure.

Figure 3. Handgrip strength quartiles and risk of clustered metabolic risk in 8–14 year old children (n = 536).

Quartile 4 is highest handgrip strength category (used as referent). Handgrip quartiles are age and sex specific handgrip/kg body mass unadjusted (grey bars) or adjusted for cardiorespiratory fitness (white bars). Clustered risk is defined as 1 SD above the age and sex specific mean. Panel A: Adjusted for Odds ratios (95% CI) for clustered metabolic risk by HG across quartiles in 8–14 year olds (n = 546) age, sex, and maturation status. Panel B: Additionally adjusted for % body fat category.

Figure 4. Handgrip strength quartiles and risk of clustered metabolic risk in 8–14 year old girls (Panel A, n = 306) and boys (Panel B, n = 330).

Quartile 4 is highest handgrip strength category (used as referent). Adjusted for age, maturation status and % body fat category (grey bars) and additionally for cardiorespiratory fitness (white bars). Clustered risk is defined as 1 SD above the age and sex specific mean.