Minna K. Salonen

Long-term consequences of maternal overweight in pregnancy on offspring later health: Findings from the Helsinki Birth Cohort Study

Abstract Introduction. Obesity has reached epidemic proportions worldwide. Maternal obesity has consequences for the offsprings later health. Only few studies have focused upon the long-term consequences of maternal obesity on the offsprings later health. Methods. A total of 13,345 men and women born in Helsinki during 1934–44 belonging to the Helsinki Birth Cohort Study were included in the study. Data on maternal weight and height in late pregnancy were available from hospital records. Using validated national registers we report on the following outcomes in relation to maternal BMI: death, cancer, coronary heart disease, stroke, and diabetes among the offspring. Results. Maternal BMI was positively associated with each of the later health outcomes of the offspring. The associations were strongest for cardiovascular disease and type 2 diabetes. The association with type 2 diabetes was stronger in women. Discussion. Our findings stress the importance of early prevention of overweight and obesity in women of child-bearing age.

Birth Weight in Relation to Leisure Time Physical Activity in Adolescence and Adulthood: Meta-Analysis of Results from 13 Nordic Cohorts

Background Prenatal life exposures, potentially manifested as altered birth size, may influence the later risk of major chronic diseases through direct biologic effects on disease processes, but also by modifying adult behaviors such as physical activity that may influence later disease risk. Methods/Principal Findings We investigated the association between birth weight and leisure time physical activity (LTPA) in 43,482 adolescents and adults from 13 Nordic cohorts. Random effects meta-analyses were performed on categorical estimates from cohort-, age-, sex- and birth weight specific analyses. Birth weight showed a reverse U-shaped association with later LTPA; within the range of normal weight the association was negligible but weights below and above this range were associated with a lower probability of undertaking LTPA. Compared with the reference category (3.26–3.75 kg), the birth weight categories of 1.26–1.75, 1.76–2.25, 2.26–2.75, and 4.76–5.25 kg, had odds ratios of 0.67 (95% confidence interval: 0.47, 0.94), 0.72 (0.59, 0.88), 0.89 (0.79, 0.99), and 0.65 (0.50, 0.86), respectively. The shape and strength of the birth weight-LTPA association was virtually independent of sex, age, gestational age, educational level, concurrent body mass index, and smoking. Conclusions/Significance The association between birth weight and undertaking LTPA is very weak within the normal birth weight range, but both low and high birth weights are associated with a lower probability of undertaking LTPA, which hence may be a mediator between prenatal influences and later disease risk.

Lower conditioning leisure-time physical activity in young adults born preterm at very low birth weight.

Background Adults born preterm at very low birth weight (VLBW, <1500 g) have elevated levels of risk factors for cardiovascular diseases and type 2 diabetes. Preliminary observations suggest that this could partly be explained by lower rates of physical activity. The aim of this study was to assess physical activity in healthy young adults born preterm at very low birth weight compared with term-born controls. Methodology/Principal Findings We studied 94 unimpaired young adults, aged 21–29 years, born at VLBW and 101 age-, sex-, and birth hospital-matched term-born controls from one regional center in Southern Finland. The participants completed a validated 30-item 12-month physical activity questionnaire and the NEO-Personality Inventory based on the Big Five taxonomy, the most commonly used classification of personality traits. Yearly frequency, total time, total volume and energy expenditure of conditioning and non-conditioning leisure-time physical activity (LTPA) and commuting physical activity were compared between VLBW and term-born subjects. A subset of participants underwent dual-energy x-ray absorptiometry for body composition measurement. Data were analyzed by multiple linear regression. Compared with controls, VLBW participants had lower frequency [−38.5% (95% CI; −58.9, −7.7)], total time [−47.4% (95% CI; −71.2, −4.1)], total volume [−44.3% (95% CI; −65.8, −9.2)] and energy expenditure [−55.9% (95% CI; −78.6, −9.4)] of conditioning LTPA when adjusted for age, sex, body mass index, smoking, parental education and personality traits. Adjusting for lean body mass instead of body mass index attenuated the difference. There were no differences in non-conditioning LTPA or commuting physical activity. Conclusions/Significance Compared with term-born controls, unimpaired VLBW adults undertake less frequent LTPA with lower total time and volume of exercise resulting in lower energy expenditure. Differences in personality that exist between the VLBW and term-born groups do not seem to explain this association.

Role of Socioeconomic Indicators on Development of Obesity from a Life Course Perspective

Aims. Development of obesity is modified by several factors, including socioeconomic ones. We studied the importance of socioeconomic indicators on the development of obesity from a life course perspective. Methods. 2003 people born 1934–1944 in Helsinki, Finland, participated in clinical examinations in 2001–2004. Obesity was defined as body mass index (BMI) >30 kg/m2. Results. Prevalence of obesity was 22.3% in men and 27.2% in women. Lower educational attainment and lower adult social class were associated with higher BMI in both men (P = .03 and P < .01) and women (P < .001 and P = .01). Childhood social class was inversely associated with BMI only in men (P < .001); lower household income was associated with higher BMI in women only (P < .001). Those men belonging to the lowest childhood social class had higher risk of being obese than those of the highest childhood social class (OR 1.8 (95% CI: 1.0–3.1)). Household income was the strongest predictor of obesity among women. Conclusion. Overweight and obesity are inversely associated with socioeconomic status. Men seem to be more susceptible to adverse childhood socioeconomic circumstances than women, while adult socioeconomic indicators were more strongly associated with obesity in women.

Depression and its association with diabetes, cardiovascular disease, and birth weight.

Background. Diabetes increases the risk for depression. Aim. To study the independent effects of diabetes mellitus (DM) and cardiovascular disease (CVD) on the prevalence of depression and to examine low birth weight as a possible common explanatory factor. Methods. 2003 subjects from the Helsinki Birth Cohort Study underwent a 75‐g oral glucose tolerance test and filled out the Beck Depression Inventory. Results. Depressive symptoms were more prevalent among subjects with diabetes (23.5%) than among those with normal glucose tolerance (16.6%) (P<0.001). A history of CVD also markedly increased the odds of having depressive symptoms (odds ratio (OR) = 2.38, 95% confidence interval (CI) = 1.70–3.32, P<0.001). The association between DM and depressive symptoms was, however, rendered non‐significant when adjusting for the presence of CVD. Being born with a low birth weight doubled the risk for having depressive symptoms (OR = 2.64, 95% CI = 1.42–4.91, P = 0.002) and magnified the association between CVD/DM and depression. Conclusion. Diabetes has only a minor independent effect on concurrent occurrence of depressive symptoms, while cardiovascular disease seems to be a more important underlying factor. The association between disease and depression is in particular characteristic to individuals born with a low birth weight.

Developmental Origins of Physical Fitness: The Helsinki Birth Cohort Study

Background Cardiorespiratory fitness (CRF) is a major factor influencing health and disease outcomes including all-cause mortality and cardiovascular disease. Importantly CRF is also modifiable and could therefore have a major public health impact. Early life exposures play a major role in chronic disease development. Our aim was to explore the potential prenatal and childhood origins of CRF in later life. Methods/Principal Findings This sub-study of the HBCS (Helsinki Birth Cohort Study) includes 606 men and women who underwent a thorough clinical examination and participated in the UKK 2-km walk test, which has been validated against a maximal exercise stress test as a measure of CRF in population studies. Data on body size at birth and growth during infancy and childhood were obtained from hospital, child welfare and school health records. Body size at birth was not associated with adult CRF. A 1 cm increase in height at 2 and 7 years was associated with 0.21 ml/kg/min (95% CI 0.02 to 0.40) and 0.16 ml/kg/min (95% CI 0.03 to 0.28) higher VO2max, respectively. Adjustment for adult lean body mass strengthened these findings. Weight at 2 and 7 years and height at 11 years became positively associated with CRF after adult lean body mass adjustment. However, a 1 kg/m2 higher BMI at 11 years was associated with −0.57 ml/kg/min (95% CI −0.91 to −0.24) lower adult VO2max, and remained so after adjustment for adult lean body mass. Conclusion/Significance We did not observe any significant associations between body size at birth and CRF in later life. However, childhood growth was associated with CRF in adulthood. These findings suggest, importantly from a public point of view, that early growth may play a role in predicting adult CRF.

Early growth and non-alcoholic fatty liver disease in adulthood—the NAFLD liver fat score and equation applied on the Helsinki Birth Cohort Study

Abstract Introduction. Prenatal and childhood growth influence the risk of developing the metabolic syndrome and type 2 diabetes. Both conditions are associated with non-alcoholic fatty liver disease (NAFLD). Our aim was to explore the associations between early growth and adult NAFLD. Methods. We studied 1587 individuals from the Helsinki Birth Cohort Study (HBCS) born 1934–44 for whom birth, childhood, and adult clinical data were available. NAFLD was defined using the NAFLD liver fat score and equation. The score was converted into a dichotomous variable, with outcomes defined as either a positive or negative score. The equation predicts liver fat percentage. Results. A positive score was found in 43% of men and 22.5% of women. Several measurements of birth and childhood body size were negatively associated with both NAFLD outcomes after adjustment for adult BMI. Those from the smallest BMI tertile at age 2 who were obese in adulthood had an OR of 18.5 for a positive score compared to those from the same group who were normal weight in adulthood. Conclusions. A larger childhood body size was negatively associated with NAFLD outcomes. Individuals who are small during early childhood and obese as adults seem to be at the highest risk of developing NAFLD.

Birth Size and Childhood Growth as Determinants of Physical Functioning in Older Age The Helsinki Birth Cohort Study

The study reports on the associations of infant and childhood anthropometric measurements, early growth, and the combined effect of birth weight and childhood body mass index with older age physical functioning among 1,999 individuals born in 1934-1944 and belonging to the Helsinki Birth Cohort Study. Physical functioning was assessed by the Short Form 36 scale. Anthropometric data from infancy and childhood were retrieved from medical records. The risk of lower Short Form 36 physical functioning at the mean age of 61.6 years was increased for those with birth weight less than 2.5 kg compared with those weighing 3.0-3.5 kg at birth (odds ratio (OR) = 2.73, 95% confidence interval (CI): 1.57, 4.72). The gain in weight from birth to age 2 years was associated with decreased risk of lower physical functioning for a 1-standard deviation increase (OR = 0.84, 95% CI: 0.75, 0.94). The risk of lower physical functioning was highest for individuals with birth weight in the lowest third and body mass index at 11 years of age in the highest third compared with those whose birth weight was in the middle third and body mass index at age 11 years was in the highest third (OR = 3.08, 95% CI: 1.83, 5.19). The increasing prevalence of obesity at all ages and the aging of populations warrant closer investigation of the role of weight trajectories in old age functional decline.

Early life body mass trajectories and mortality in older age: Findings from the Helsinki Birth Cohort Study

Abstract Background. Overweight and obesity in childhood have been linked to an increased risk of adult mortality, but evidence is still scarce. Methods. We identified trajectories of body mass index (BMI) development in early life and investigated their mortality risk. Data come from the Helsinki Birth Cohort Study, in which 4943 individuals, born 1934–1944, had serial measures of weight and height from birth to 11 years extracted from health care records, weight and height data in adulthood, and register-based mortality data for 2000–2010. Results. Three early BMI trajectories (increasing, average, and average-to-low for men and increasing, average, and low-to-high BMI for women) were identified. Women with an increasing or low-to-high BMI (BMI lower in early childhood, later exceeded average) trajectory had an increased risk of all-cause mortality compared to those with an average BMI trajectory (HR 1.55, 95% CI 1.07–2.23; and HR 1.57, 95% CI 1.04–2.37, respectively). Similar associations were observed for cancer mortality. Among men, BMI trajectories were not associated with all-cause mortality, but those with average-to-low BMI (BMI first similar then dropped below average) had an increased risk of cancer mortality. Conclusions. An increasing BMI in early life may shorten the lifespan of maturing cohorts as they age, particularly among women.

Physical Activity, Body Composition and Metabolic Syndrome in Young Adults

Objective Low physical activity (PA) is a major risk factor for cardiovascular and metabolic disorders in all age groups. We measured intensity and volume of PA and examined the associations between PA and the metabolic syndrome (MS), its components and body composition among young Finnish adults. Research Design and Methods The study comprises 991 men and women born 1985-86, who participated in a clinical study during the years 2009-11 which included assessments of metabolism, body composition and PA. Objectively measured (SenseWear Armband) five-day PA data was available from 737 participants and was expressed in metabolic equivalents of task (MET). Results The prevalence of MS ranged between 8-10%. Higher total mean volume (MET-hours) or intensity (MET) were negatively associated with the risk of MS and separate components of MS, while the time spent at sedentary level of PA was positively associated with MS. Conclusions MS was prevalent in approximately every tenth of the young adults at the age of 24 years. Higher total mean intensity and volume rates as well as longer duration spent at moderate and vigorous PA level had a beneficial impact on the risk of MS. Longer time spent at the sedentary level of PA increased the risk of MS.