C LIU1, Y HE1, M JOSE2, B FRASER1, C MAGNUSSEN1,3, T DWYER1,4, A VENN1
1Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia, 2School of Medicine, University of Tasmania, Hobart, Australia, 3Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku, Turku, Finland, 4The George Institute for Global Health, University of Oxford, Oxford, United Kingdom
Aim: To investigate the relationship of childhood cardiorespiratory fitness (CRF) with midlife albuminuria and glomerular hyperfiltration (GHF).
Background: GHF and albuminuria are known to be the predictors of kidney disease. Higher CRF in adulthood has been reported to be associated with a lower risk of developing kidney disease. Little is known about the association of childhood CRF with GHF and albuminuria in midlife.
Methods: This study involved a 32-year follow-up of 1,121 participants aged 36-50 years who participated in the 1985 Australian Schools Health and Fitness Survey when they were 7-15 years old. Childhood CRF was estimated by the time of a 1.6 km run. At follow-up, participants attended study clinics where fasting blood and urine samples were collected, and urine albumin-to-creatinine ratio (UACR) calculated. Log-binomial regression was used to determine the associations of childhood CRF with GHF [estimated glomerular filtration rate (mL/min/1.73m²)>95th percentile after standardised for age and sex] and albuminuria [UACR≥2.5mg/mmol (males) or ≥ 3.5mg/mmol (females)] in midlife.
Results: Compared with females with high childhood CRF, those with lower childhood CRF had a higher risk of GHF in midlife after adjusting for childhood age, socio-economic position and follow-up length [relative risk (RR)=2.78, 95% confidence interval (CI), 0.90-8.59 for individuals with moderate CRF, and RR=5.27, 95% CI, 1.66-16.72 for individuals with low childhood CRF; P-trend=0.003]. Further adjustment for childhood body mass index (BMI) z-score and adult BMI attenuated the association but it remained significant (P-trend=0.032). Associations with GHF were not found for males. No significant associations were found with albuminuria in males or females.
Conclusions: In this population-based Australian cohort, low childhood CRF appeared to increase the risk of GHF in midlife in females.
Conghui Liu completed her Bachelor of Medicine in 2015 and Master of Medicine in 2018. She is now the PhD candidate in the Menzies Institute for Medical Research at the University of Tasmania. Her research interest is about understanding the life-course factors from childhood to adulthood that predict kidney damage in midlife.