Early life origins cognitive decline: findings in elderly men in the Helsinki Birth Cohort Study.

OBJECTIVES: To examine whether the adverse effects of slow prenatal and postnatal growth on cognitive function persist to old age and predict age related cognitive decline. DESIGN AND SETTING: A longitudinal birth cohort study of men born in Helsinki, Finland 1934-44. PARTICIPANTS: Nine-hundred-thirty-one men of the Helsinki Birth Cohort Study, with detailed data on growth from birth to adulthood, aged 20.1 (SD = 1.4) at the first and 67.9 (SD = 2.5) years at the second cognitive testing. MAIN OUTCOME MEASURES: The Finnish Defense Forces Basic Intellectual Ability Test assessed twice over nearly five decades apart. RESULTS: Lower weight, length and head circumference at birth were associated with lower cognitive ability at 67.9 years (1.04-1.55 points lower ability per each standard deviation [SD] unit decrease in body size, 95% Confidence Interval [95%CI]: 0.05 to 2.72) and with cognitive decline after 20.1 years (0.07-0.11 SD decline over time per each SD decrease in body size, 95%CI:0.00 to 0.19). Men who were born larger were more likely to perform better in the cognitive ability test over time (1.22-1.43 increase in odds to remain in the top relative to the lower two thirds in ability over time per each SD increase in body size, 95%CI:1.04 to 1.79) and were more resilient to cognitive decline after 20.1 years (0.69 to 0.76 decrease in odds to decline from than remain in the top third of ability over time per each SD increase in body size, 95%CI:0.49 to 0.99). Slower growth between birth and two years in weight, height and body mass index was associated with lower cognitive ability at 67.9 years, but not with cognitive decline. CONCLUSIONS: Poorer lifetime cognitive ability is predicted by slower growth before and after birth. In predicting resilience to age related cognitive decline, the period before birth seems to be more critical.

Stroke is predicted by low visuospatial in relation to other intellectual abilities and coronary heart disease by low general intelligence.

BACKGROUND: Low intellectual ability is associated with an increased risk of coronary heart disease and stroke. Most studies have used a general intelligence score. We studied whether three different subscores of intellectual ability predict these disorders. METHODS: We studied 2,786 men, born between 1934 and 1944 in Helsinki, Finland, who as conscripts at age 20 underwent an intellectual ability test comprising verbal, visuospatial (analogous to Raven's progressive matrices) and arithmetic reasoning subtests. We ascertained the later occurrence of coronary heart disease and stroke from validated national hospital discharge and death registers. RESULTS: 281 men (10.1%) had experienced a coronary heart disease event and 131 (4.7%) a stroke event. Coronary heart disease was predicted by low scores in all subtests, hazard ratios for each standard deviation (SD) lower score ranging from 1.21 to 1.30 (confidence intervals 1.08 to 1.46). Stroke was predicted by a low visuospatial reasoning score, the corresponding hazard ratio being 1.23 (95% confidence interval 1.04 to 1.46), adjusted for year and age at testing. Adjusted in addition for the two other scores, the hazard ratio was 1.40 (1.10 to 1.79). This hazard ratio was little affected by adjustment for socioeconomic status in childhood and adult life, whereas the same adjustments attenuated the associations between intellectual ability and coronary heart disease. The associations with stroke were also unchanged when adjusted for systolic blood pressure at 20 years and reimbursement for adult antihypertensive medication. CONCLUSIONS: Stroke is predicted by low visuospatial reasoning scores in relation to scores in the two other subtests. This association may be mediated by common underlying causes such as impaired brain development, rather than by mechanisms associated with risk factors shared by stroke and coronary heart disease, such as socio-economic status, hypertension and atherosclerosis.

Hypertensive disorders in pregnancy and cognitive decline in the offspring up to old age.

OBJECTIVE: We tested whether maternal hypertensive disorders in pregnancy predict age-related change in cognitive ability in the offspring up to old age. METHODS: Using mothers' blood pressure and urinary protein measurements from the maternity clinics and birth hospitals, we defined normotensive or hypertensive pregnancies in mothers of 398 men, who participated in the Helsinki Birth Cohort 1934-1944 Study. The men underwent the Finnish Defence Forces basic ability test twice: first during compulsory military service at age 20.1 (SD = 1.4) years and then in a retest at age 68.5 (SD = 2.9) years. The test yields a total score and subscores for tests measuring verbal, arithmetic, and visuospatial reasoning. RESULTS: Men born after pregnancies complicated by a hypertensive disorder, compared with men born after normotensive pregnancies, scored 4.36 (95% confidence interval, 1.17-7.55) points lower on total cognitive ability at 68.5 years and displayed a greater decline in total cognitive ability (2.88; 95% confidence interval, 0.07-5.06) after 20.1 years. Of the subscores, associations were strongest for arithmetic reasoning. CONCLUSION: Maternal hypertensive disorders in pregnancy predict lower cognitive ability and greater cognitive decline up to old age. A propensity to lower cognitive ability and decline up to old age may have prenatal origins.

Hypertensive disorders in pregnancy and intellectual abilities in the offspring in young adulthood: the Helsinki Birth Cohort Study.

BACKGROUND: Hypertensive disorders may affect the fetal developmental milieu and thus hint at mechanisms by which prenatal adversity associates with poorer intellectual ability in subsequent life. AIM: We tested if hypertensive disorders in pregnancy are associated with intellectual ability in the offspring in young adulthood and if any potential associations between hypertensive disorders and intellectual abilities differ according to length of gestation, birth-weight, parity, and childhood socio-economic background. METHODS: Using mothers' blood pressure and urinary protein measurements at maternity clinics and birth hospitals, we defined normotensive or hypertensive pregnancies in mothers of 1,196 men who participated in the Helsinki Birth Cohort 1934-1944 Study. At age 20 years the men completed a test on intellectual abilities during compulsory military service. RESULTS: Participants born after pregnancies complicated by hypertensive disorders scored lower on intellectual abilities compared to those born after normotensive pregnancies. The effects of hypertensive disorders were most obvious in men born preterm or after a primiparous pregnancy and in men of higher childhood socio-economic background. CONCLUSION: Hypertensive disorders in pregnancy are, albeit weakly, associated with lower intellectual abilities in the offspring. These findings are compatible with the concept of adverse fetal 'programming' by a suboptimal prenatal environment.

Growth trajectories and intellectual abilities in young adulthood: The Helsinki Birth Cohort study.

Slow childhood growth is associated with poorer intellectual ability. The critical periods of growth remain uncertain. Among 2,786 Finnish male military conscripts (1952-1972) born in 1934-1944, the authors tested how specific growth periods from birth to age 20 years predicted verbal, visuospatial, and arithmetic abilities at age 20. Small head circumference at birth predicted poorer verbal, visuospatial, and arithmetic abilities. The latter 2 measures were also associated with lower weight and body mass index (weight (kg)/height (m)(2)) at birth (for a 1-standard-deviation (SD) decrease in test score per SD decrease in body size > or = 0.05, P's < 0.04). Slow linear growth and weight gain between birth and age 6 months, between ages 6 months and 2 years, or both predicted poorer performance on all 3 tests (for a 1-SD decrease in test score per SD decrease in growth > or = 0.05, P's < 0.03). Reduced linear growth between ages 2 and 7 years predicted worse verbal ability, and between age 11 years and conscription it predicted worse performance on all 3 tests. Prenatal brain growth and linear growth up to 2 years after birth form a first critical period for intellectual development. There is a second critical period, specific for verbal development, between ages 2 and 7 years and a third critical period for all 3 tested outcomes during adolescence.

Intellectual ability in early adulthood and type 2 diabetes in later life.

The aim of this study is to assess whether intellectual ability in young adult men predicts the development of type 2 diabetes in later life. 641 men participating in the Helsinki Birth Cohort Study were administered a 2-h (75 g) oral glucose tolerance test at a mean age of 61 years. Intellectual ability was assessed during compulsory military service at a mean age of 20 years. Associations were explored using linear and logistic regression models. Intellectual ability in young adulthood did not predict glucose tolerance at age 61 years. However, educational attainment was associated with the prevalence of type 2 diabetes, independently of early intellectual ability. Men with the highest educational attainment were less likely to have type 2 diabetes than men with the lowest educational attainment (OR = 0.50, 95% CI 0.28-0.91). While education seems to protect from type 2 diabetes, we could not detect a connection between early intellectual ability and impairment in glucose regulation in later adulthood.