Low birth weight
A risk factor for development of kidney disease
- A systematic review
Jung-Fu Chiang, Claire Carson*
Chiang’s Medical Clinic,Ganshan Town, Kaohsiung Shian, Taiwan
Department of Epidemiology and Population Health, London School of
Hygiene and Tropical Medicine, London, United Kingdom*
Background：People born with low birth weight are prone to develop diabetes mellitus, low nephron number and subsequent essential hypertension. The cause of end stage renal disease is multifactorial. Low birth weight has been proposed to be a risk of renal disease.
Objectives：The aim of this review is to assess the quality of study methods of included studies and to discuss evidence for any association between low birth weight and renal disease in diabetic and non-diabetc people.
Search strategy：MEDLINE and EMBASE were searched for related English articles with no date limitation and focused on humans. Hand-searching on core kidney journals, and the reference lists of these selected articles were scrutinized.
Selection criteria：Cross-sectional studies, cohort studies, and case-control studies exploring association between low birth weight and kidney disease were included. Case reports, experimental animal studies, narrative review and chronic pyelonephritis cases were excluded.
Data collection and analysis: Eligible articles were extracted for data regarding the study method, exposure of interest, outcome of interest, non-participation rate, blinding status of observers and participants, outcome assessment, and confounders adjustment.
Main results：Among studies on diabetic people, association between low birth weight and renal disease is mixed but among studies on non-diabetic people, low birth weight tends to be inversely associated with renal disease. Author’s conclusions: Fetal origins hypothesis is plausible, evidence should be critically appraised in terms of methodological quality. For a future work, a well-designed cohort study to follow up low birth weight babies should be recommended. Exposure measurement (birth weight) should be measured adjusting for gestational age. Outcome measurement must be standardized, i.e. - using microalbuminuria to identify early diabetic nephropathy in diabetic people and using urine ACR≧30mg/mmol to detect early nephropathy in non-diabetic people. Additional potential confounders, such as socio-economic level, postnatal growth, and current weight, should be adjusted when assessing the effect of low birth weight on renal disease.
Key words : low birth weight, low nephron number, nephropathy