Preterm Birth and the Metabolic Syndrome in Adult Life: A Systematic Review and Meta-analysis

Abstract

BACKGROUND: Preterm birth is associated with features of the metabolic syndrome in later life. We performed a systematic review and meta-analysis of studies reporting markers of the metabolic syndrome in adults born preterm. METHODS: Reports of metabolic syndrome–associated features in adults (≥18 years of age) born at <37-week gestational age and at term (37- to 42-week gestational age) were included. Outcomes assessed were BMI, waist-hip ratio, percentage fat mass, systolic (SBP) and diastolic (DBP) blood pressure, 24-hour ambulatory SBP and DBP, flow-mediated dilatation, intima-media thickness, and fasting glucose, insulin, and lipid profiles. RESULTS: Twenty-seven studies, comprising a combined total of 17 030 preterm and 295 261 term-born adults, were included. In adults, preterm birth was associated with significantly higher SBP (mean difference, 4.2 mm Hg; 95% confidence interval [CI], 2.8 to 5.7; P < .001), DBP (mean difference, 2.6 mm Hg; 95% CI, 1.2 to 4.0; P < .001), 24-hour ambulatory SBP (mean difference, 3.1 mm Hg; 95% CI, 0.3 to 6.0; P = .03), and low-density lipoprotein (mean difference, 0.14 mmol/L; 95% CI, 0.05 to 0.21; P = .01). The preterm–term differences for women was greater than the preterm–term difference in men by 2.9 mm Hg for SBP (95% CI [1.1 to 4.6], P = .004) and 1.6 mm Hg for DBP (95% CI [0.3 to 2.9], P = .02). CONCLUSIONS: For the majority of outcome measures associated with the metabolic syndrome, we found no difference between preterm and term-born adults. Increased plasma low-density lipoprotein in young adults born preterm may represent a greater risk for atherosclerosis and cardiovascular disease in later life. Preterm birth is associated with higher blood pressure in adult life, with women appearing to be at greater risk than men.