Background: Low birthweight (BW) and childhood growth have been hypothesized to be associated with an increased risk of hypertension in later life.
Methods: We analysed data among 13,467 women with a recalled BW from the Shanghai Women's Health Study. Cases included those with a self-reported hypertension with ('confirmed cases') or without ('possible cases') antihypertensive medication(s) use. Logistic regression was used to derive adjusted odds ratios (OR) and 95% CI.
Results: Birthweight was inversely associated with the odds of early onset (at age 20-40 years) hypertension in a dose response manner (P for trend = 0.01). This association is stronger for 'confirmed' hypertension (only OR for 'confirmed' hypertension are referred to subsequently). Being heavier or taller than average at 15 years of age were both related to elevated odds of early onset hypertension. Women who had a low BW but were heavier than average at age 15 were more than four times (OR = 4.63, 95% CI: 2.40-8.94) more likely to have an early onset hypertension, and those who had a low BW and became taller at 15 years of age had an OR of 1.87 (95% CI: 1.05-3.31). A significant interaction between BW and weight at age 15 was observed (P = 0.04).
Conclusion: Our study suggests that low BW, particularly if accompanied by accelerated childhood growth, may increase the risk of early onset hypertension in adulthood.