Cardiometabolic risk factors in children born with marginally low birth weight: A longitudinal cohort study up to 7 years-of-age

Abstract

Introduction: Low birth weight (LBW, <2500 g) may predict an increased risk of an adverse cardiometabolic profile later in life, but long-term effects in different populations and birth weight strata are still unclear. We explored laboratory markers of cardiometabolic risk in children born with marginally LBW (2000-2500 g).

Methods: This was a prospective longitudinal cohort study including 285 Swedish marginally LBW children and 95 normal birth weight (NBW, 2501-4500 g) controls. At 3.5 and 7 years of age, blood samples for glucose, insulin, homeostatic model assessment for insulin resistance (HOMA-IR), cholesterol, triglycerides, high- and low density lipoprotein (HDL and LDL), apolipoprotein B (ApoB) and apolipoprotein A1 (ApoA1) were assessed and compared between the groups.

Results: No significant differences in levels of insulin, HOMA-IR, hs-CRP or blood lipids were observed between marginally LBW and NBW children. At 7 years there was a higher proportion of marginally LBW children with elevated levels of insulin, defined as above the 90th percentile of the control group (21% vs 8.6%, p = 0.038). This association was, however, confounded by maternal ethnicity. In marginally LBW children born small for gestational age (SGA), mean fasting glucose was significantly higher compared to controls (4.7 vs 4.5 mmol/L, p = 0.020).

Conclusions: There were no significant differences in insulin, insulin resistance, hs-CRP or blood lipids between the marginally LBW children and controls. The subgroup of marginally LBW children born SGA may present early signs of glucose imbalance already at school age.

Fig 1. Study flow chart.

Study flow chart of 285 marginally low birth weight (marginally LBW) infants and 95 control children born with normal birth weight (NBW). Four infants were excluded due to congenital disorders. Four of the marginally LBW children did not attend the 3.5 year visit but did attend the 7 year visit. The marginally LBW children were also stratified for being born small- or appropriate for gestational age (SGA and AGA respectively).

Fig 2. Prevalence of elevated cardiometabolic markers in marginally LBW children compared to controls.

The prevalence of children with elevated markers of cardiometabolic risk (subnormal levels for HDL) at 7 years of age in 191 marginally low birth weight (marginally LBW) compared to 65 control children born with normal birth weight. P-values are Chi-square test for group comparison.