TABLE 2.
Overall and sub-group meta-analysis of the associations between hair cortisol concentration and adiposity-related outcome(s) among children based on 20 included studies.
| Heterogeneity |
|||||||||
| Sample | Adiposity-related outcome(s) |
N of studies |
Effect size (β, 95% CI) |
P-value | I2 (%) | χ2 | P-value | Tau-squared | P-value (Egger’s test)e |
| (1) Cross-sectional studies (β, 95% CI) | |||||||||
| Overall | FMI-SDS/FMI z-score | 2 | 0.08 (−0.06, 0.22) | 024 | 82.1 | 5.60 | 0.02 | 0.01 | – |
| Overalla | BMI/BMI z-score | 8 | 0.15 (0.06, 0.25) | 0.002 | 99.7 | 2,200.16 | <0.001 | 0.01 | 0.69 |
| Age group | |||||||||
| ≤12 years | BMI/BMI z-score | 6 | 0.15 (0.05, 0.26) | <0.001 | 99.8 | 2,199.92 | <0.001 | 0.01 | |
| >12 years | BMI/BMI z-score | 2 | 0.13 (0.04, 0.22) | 0.004 | 0 | 0.02 | 0.90 | <0.001 | |
| Country developmental context | |||||||||
| Developed countries | BMI/BMI z-score | 6 | 0.12 (0.03, 0.21) | <0.001 | 88.4 | 43.22 | <0.001 | 0.01 | |
| Developing countries | BMI/BMI z-score | 2 | 0.193 (0.188, 0.198) | <0.001 | 0 | 0.14 | 0.71 | <0.001 | |
| Measurement method | |||||||||
| LC-MS/MS | BMI/BMI z-score | 3 | 0.18 (0.06, 0.29) | 0.002 | 99.8 | 2186.67 | <0.001 | 0.01 | |
| ELISA | BMI/BMI z-score | 5 | 0.08 (−0.06, 0.22) | 0.26 | 65.1 | 5.74 | 0.06 | 0.01 | |
| (2) Cross-sectional studies (r, 95% CI) | |||||||||
| Overalla,c | Waist circumference | 4 | 0.16 (0.03, 0.28) | 0.01 | 50.5 | 6.07 | 0.11 | 0.01 | 0.449 |
| Measurement method | |||||||||
| ELISA | Waist circumference | 3 | 0.19 (0.03, 0.40) | 0.01 | 67.0 | 6.06 | 0.05 | 0.02 | |
| CLIAd | Waist circumference | 1 | 0.14 (0.03, 0.25) | – | – | – | – | – | |
| Overallc | BMI/BMI z-score/BMI-SDS | 6 | 0.08 (−0.09, 0.26) | 0.35 | 78.5 | 23.29 | <0.001 | 0.04 | 0.918 |
| Measurement method | |||||||||
| ELISA | BMI/BMI z-score/BMI-SDS | 3 | 0.02 (−0.32, 0.35) | 0.93 | 84.5 | 12.88 | 0.002 | 0.07 | |
| LC-MS/MS | BMI/BMI z-score/BMI-SDS | 2 | 0.16 (−0.16, 0.48) | 0.33 | 69.8 | 3.31 | 0.07 | 0.04 | |
| Sexb | |||||||||
| Boysd | BMI/BMI z-score | 1 | 0.13 (−0.03, 0.29) | – | – | – | – | – | |
| Girls | BMI/BMI z-score | 2 | 0.21 (0.06, 0.36) | 0.003 | 13.9 | 1.16 | 0.28 | <0.001 | |
FMI, fat mass index; BMI, body mass index; SDS, standard deviation score; ELISA, Enzyme-Linked Immunosorbent Assay; LC–MS/MS, liquid chromatography tandem mass spectrometry; CLIA, chemiluminescence immunoassay.
We had searched two cohort studies that reported the associations (β, 95% CI) between hair cortisol concentration and adiposity, one of the studies showed that the associations between hair cortisol concentration and BMI: β (95% CI) = 4.62 (1.41, 7.83) (p < 0.01), the other one’s effective size has different meaning. Thus, we were unable to perform a meta-analysis.
aThese studies did not report the associations between cortisol and adiposity for boys and girls, respectively. Thus, we did not do the subgroups analysis across genders, country context, or age groups.
bAmong the six studies showed association (r) between hair cortisol concentration and weight status, only one reported the association for boys and girls. We divided the article into two studies and one study only showed the association for girls.
cThese studies were all from developed countries and the participants were ≤12 years old, thus, we did not perform sub-group meta-analysis across country context and age groups.
dIn the sub-group meta-analysis, only one study was included and the effect size was the one reported in the original study.
eThe Egger’s tests was used to indicate the existence of publication bias. If p-value < 0, it was indicated that publication bias was existed, otherwise, no publication bias existed. Numbers in bold indicate significance.