Insufficient Fruit and Vegetable Intake and Low Potassium Intake Aggravate Early Renal Damage in Children: A Longitudinal Study

Abstract

Insufficient fruit and vegetable intake (FVI) and low potassium intake are associated with many non-communicable diseases, but the association with early renal damage in children is uncertain. We aimed to identify the associations of early renal damage with insufficient FVI and daily potassium intake in a general pediatric population. We conducted four waves of urine assays based on our child cohort (PROC) study from October 2018 to November 2019 in Beijing, China. We investigated FVI and other lifestyle status via questionnaire surveys and measured urinary potassium, β2-microglobulin (β2-MG), and microalbumin (MA) excretion to assess daily potassium intake and renal damage among 1914 primary school children. The prevalence of insufficient FVI (<4/d) was 48.6% (95% CI: 46.4%, 50.9%) and the estimated potassium intake at baseline was 1.63 ± 0.48 g/d. Short sleep duration, long screen time, lower estimated potassium intake, higher β2-MG and MA excretion were significantly more frequent in the insufficient FVI group. We generated linear mixed effects models and observed the bivariate associations of urinary β2-MG and MA excretion with insufficient FVI (β = 0.012, 95% CI: 0.005, 0.020; β = 0.717, 95% CI: 0.075, 1.359), and estimated potassium intake (β = −0.042, 95% CI: −0.052, −0.033; β = −1.778, 95% CI: −2.600, −0.956), respectively; after adjusting for age, sex, BMI, SBP, sleep duration, screen time and physical activity. In multivariate models, we observed that urinary β2-MG excretion increased with insufficient FVI (β = 0.011, 95% CI: 0.004, 0.018) and insufficient potassium intake (<1.5 g/d) (β = 0.031, 95% CI: 0.023, 0.038); and urinary MA excretion increased with insufficient FVI (β = 0.658, 95% CI: 0.017, 1.299) and insufficient potassium intake (β = 1.185, 95% CI: 0.492, 1.878). We visualized different quartiles of potassium intake showing different renal damage with insufficient FVI for interpretation and validation of the findings. Insufficient FVI and low potassium intake aggravate early renal damage in children and underscores that healthy lifestyles, especially adequate FVI, should be advocated.

Interaction of Hydration Status and Physical Activity Level on Early Renal Damage in Children: A Longitudinal Study

“…Z-scores of height, weight, and body mass index (BMI) were calculated using 2007 WHO standards and standardized SBP was calculated by age and sex group. Lifestyle information were reported by parents using self-administrated questionnaires, including sleep duration (Children's Sleep Habits Questionnaire [CSHQ]) ( 26 , 27 ), fruit and vegetable intake (FVI; 16-item Mediterranean Diet Quality Index in children and adolescents [KIDMED]) ( 23 , 28 ), and computer/cell phone screen time and PA time (self-administrated questionnaire, including 17 activities indoor and outdoor lasting at least 15 min, based on Children's Leisure Activities Study Survey Chinese version [CLASS-C]) ( 29 ). Short sleep for children was defined as sleep duration <10 h/day.…”

“…ChiCTR2100044027, official website as https://www.procstudy.com ) enrolled 1,914 children aged 6–8 years newly in six non-boarding primary schools in Beijing in 2018 [detailed elsewhere ( 22 )]. All participants were recruited from the PROC cohort and were followed for four waves of repeated urine assays from October 2018 to November 2019 [detailed elsewhere ( 23 )]. In brief, the wave 1 of urine assay was conducted at baseline and waves 2–4 of urine assays were conducted within a 1-week span periodically during the 1-year follow-up visit ( Figure 1 ).…”

“…Urine collection and test procedures were detailed elsewhere ( 23 ). In brief, fasting urine assays were conducted at baseline in wave 1, 24-h urine assays were conducted from Sunday to Monday in wave 2, and fasting urine assays were conducted on Wednesday in wave 3 and Friday in wave 4.…”

“…Anthropometric measurements were conducted by trained staff and included height, weight, BMI, and blood pressure [detailed elsewhere ( 23 )]. Z-scores of height, weight, and body mass index (BMI) were calculated using 2007 WHO standards and standardized SBP was calculated by age and sex group.…”

Dietary, Lifestyle, and Children Health

“…These studies reported that moderate fruit consumption was associated with lower odds of lipid disorders [ 2 ] and that high fruit and vegetable intake (FVI) could reduce asthma-related illness [ 3 ]. However, insufficient FVI and low potassium intake aggravate early renal damage in children [ 4 ]. Cereals are a major source of dietary energy and a good source of many micronutrients and dietary fiber.…”