Effect of Intrauterine Growth Restriction on Kidney Function at Young Adult Age: The Nord Trøndelag Health (HUNT 2) Study
Received 18 May 2007; accepted 24 September 2007.
Refers to article:
Weight for Gestational Age as a Baseline Predictor of Kidney Function in Adulthood
Julie R. Ingelfinger
American Journal of Kidney Diseases
January 2008 (Vol. 51, Issue 1, Pages 1-4) Full Text |
Full-Text PDF (88 KB)
Background
The hypothesis of intrauterine origin of adult disease is debated. We tested whether intrauterine growth restriction is associated with later kidney function.
Study Design
Prospective cohort study.
Setting & Participants
7,457 Norwegian adults aged 20 to 30 years participating in the population-based Nord Trøndelag Health Study (1995-1997) with data for birth weight, gestational age, and maternal and perinatal risk factors registered at the Medical Birth Registry of Norway.
Predictor
Birth weight expressed as an SD score (SDS) to adjust for gestational age and sex. Subjects with a birth weight SDS less than −2.0, −2.0 to −1.3, and −1.3 to 1.3 were defined as very small, small, and appropriate for gestational age, corresponding to less than the 3rd, 3rd to 10th, and 10th to 90th percentiles, respectively.
Outcome & Measurements
Kidney function estimated using the Cockcroft-Gault and isotope dilution mass spectrometry–traceable 4-variable Modification of Diet in Renal Disease (MDRD) Study equation. Values less than the sex-specific 10th percentile were defined as low-normal kidney function.
Results
Compared with men with birth weight appropriate for gestational age (n = 2,755), odds ratios for low-normal creatinine clearance (<100 mL/min) were 1.66 (95% confidence interval [CI], 1.16 to 2.37) if small for gestational age (n = 261) and 2.40 (95% CI, 1.46 to 3.94) if very small for gestational age (n = 101). Kidney function estimated using the MDRD Study equation gave similar results. Women (n = 3,126, 283, and 112, respectively) had odds ratios of 1.65 (95% CI, 1.17 to 2.35) and 2.00 (95% CI, 1.21 to 3.29) for low-normal creatinine clearance (<80 mL/min), whereas the association was not significant using the MDRD Study equation. Using linear regression, creatinine clearance decreased by 4.0 mL/min (95% CI, 3.3 to 4.6) in men and 2.9 mL/min (95% CI, 2.2 to 3.5) in women per 1-SDS decrease. Adjusting for possible confounders did not influence results.
Limitations
Selection bias could be a problem because the participation rate was 49%, but there were no statistically significant differences between participants and nonparticipants regarding maternal and perinatal characteristics. Adjusting kidney function for body size can be a special problem in people with intrauterine growth restriction.
Conclusions
Although effects were still small in young adulthood, intrauterine growth restriction was significantly associated with low-normal kidney function. The effect was weaker and less consistent in women compared with men.
1Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway
2Department of Medicine, Division of Nephrology, St Olav University Hospital, Trondheim, Norway
3Department of Clinical Epidemiology, Leiden University Medical Centre, Leiden, The Netherlands
4Medical Birth Registry of Norway, Locus of Registry Based Epidemiology, University of Bergen and Norwegian Institute of Public Health, Oslo, Norway
5Department of Public Health and Primary Health Care, University of Bergen, Norway
6Department of Pediatrics, Leiden University Medical Centre, Leiden, The Netherlands
7Department of Community Medicine and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway
Address correspondence to Stein Hallan, MD, PhD, Department of Medicine, Division of Nephrology, St Olavs Hospital, Olav Kyrres gt 17, N-7000 Trondheim, Norway.
ABSTRACT