Temporal trends in renal function and birthweight in Japanese adolescent males (1998-2015)

Area of Science:

• Public Health
• Nephrology
• Pediatrics

Background:

• Low birthweight (LBW) is a growing global public health issue, with increasing rates observed in developed nations like Japan.
• LBW is recognized as a significant risk factor for the subsequent development of chronic kidney disease (CKD).
• Previous research has not comprehensively assessed the population-level effects of rising LBW rates on kidney function.

Purpose of the Study:

• To investigate the association between increasing rates of low birthweight (LBW) and the prevalence of reduced renal function in Japanese adolescents.
• To evaluate the population impact of LBW trends on estimated glomerular filtration rate (eGFR) over an 18-year period.

Main Methods:

• Utilized annual cross-sectional data from 3737 Japanese adolescent males aged 15-16 years, spanning from 1998 to 2015.
• Analyzed changes in mean birthweight, LBW rates, mean eGFR, and the prevalence of mildly reduced renal function (eGFR < 90 mL/min/1.73 m²).
• Assessed the association between LBW and mildly reduced renal function using statistical analysis, including odds ratios.

Main Results:

• Between 1998-2003 and 2010-2015, mean birthweight decreased, and the LBW rate rose from 2.5% to 5.5% (P≤0.01).
• Mean eGFR declined, and the prevalence of mildly reduced renal function increased significantly from 16.4% to 30.0% (P≤0.01), particularly in the LBW group (10.3% to 41.7%).
• Proteinuria prevalence also increased significantly, with mildly reduced renal function being significantly associated with LBW (OR 1.51, P=0.047).

Conclusions:

• A rise in the frequency of mildly reduced renal function was observed concurrently with an increase in LBW frequency among Japanese adolescents.
• These findings suggest potential long-term implications for the renal health of the broader Japanese population and other global populations experiencing increasing LBW rates.