Decreased heart rate variability in children born with low birth weight

BACKGROUND: Low birth weight (LBW) is associated with cardiovascular morbidity in adulthood. Imbalance in the autonomic nervous system (ANS) has been implicated as a mechanism behind the developmental programming of cardiovascular function. We hypothesized that deviations in the ANS function are seen in children born with LBW. METHODS: Eighty-six children were included: 31 born pre-term (<32 wk gestational age), 27 born at term but small for gestational age (SGA), and 28 born at term with normal birth weight (control). Twenty-four-hour Holter-electrocardiogram monitoring was performed at an average age of 9 y. Heart rate variability results were analyzed using frequency and time domain methods. RESULTS: All frequency components and both time domain parameters tested were significantly lower in the preterm and SGA children compared with controls. The low frequency/high frequency ratio was not significantly different between children born with LBW and controls. CONCLUSION: The autonomic control appears to be affected in children born with LBW despite gestational age at birth. Decreased total power, as an estimation of the ANS's global activity, rather than the balance between parasympathetic and sympathetic modulation might be an early marker of cardiovascular disease later on in life for LBW born children.