Prolonged sleep restriction induces changes in pathways involved in cholesterol metabolism and inflammatory responses

Sleep loss and insufficient sleep are risk factors for cardiometabolic diseases, but data on how insufficient sleep contributes to these diseases are scarce. These questions were addressed using two approaches: an experimental, partial sleep restriction study (14 cases and 7 control subjects) with objective verification of sleep amount, and two independent epidemiological cohorts (altogether 2739 individuals) with questions of sleep insufficiency. In both approaches, blood transcriptome and serum metabolome were analysed. Sleep loss decreased the expression of genes encoding cholesterol transporters and increased expression in pathways involved in inflammatory responses in both paradigms. Metabolomic analyses revealed lower circulating large HDL in the population cohorts among subjects reporting insufficient sleep, while circulating LDL decreased in the experimental sleep restriction study. These findings suggest that prolonged sleep deprivation modifies inflammatory and cholesterol pathways at the level of gene expression and serum lipoproteins, inducing changes toward potentially higher risk for cardiometabolic diseases.

Continuous and Dichotomous Metabolic Syndrome Definitions in Youth Predict Adult Type 2 Diabetes and Carotid Artery Intima Media Thickness: The Cardiovascular Risk in Young Finns Study

OBJECTIVES

To examine the utility of continuous metabolic syndrome (cMetS) scores vs a dichotomous metabolic syndrome (MetS) definition in youth to predict adult type 2 diabetes mellitus (T2DM) and carotid intima-media thickness (IMT).

STUDY DESIGN

Participants (n = 1453) from the population-based, prospective, observational Cardiovascular Risk in Young Finns Study who were examined in youth (when aged 9-18 years) and re-examined 15-25 years later. Four cMetS scores were constructed according to procedures most often used in the literature that comprised the youth risk factor inputs of body mass index, blood pressure, glucose, insulin, high-density lipoprotein-cholesterol, and triglycerides. Adult outcomes included T2DM and high carotid IMT (≥ 90 th percentile).

RESULTS

For a 1 SD increase in cMetS scores in youth, participants had a 30%-78% increased risk of T2DM and 12%-61% increased risk of high carotid IMT. Prediction of adult T2DM and high carotid IMT using cMetS scores in youth was essentially no different to a dichotomous MetS definition with area under the receiver-operating characteristic curve ranging from 0.54-0.60 (continuous definitions) and 0.55-0.59 (dichotomous) with 95% CIs often including 0.5, and integrated discrimination improvement from -0.2% to -0.6%.

CONCLUSIONS

cMetS scores in youth are predictive of cardiometabolic outcomes in adulthood. However, they do not have increased predictive utility over a dichotomous definition of MetS.

Longitudinal study of circulating oxidized LDL and HDL and fatty liver: the Cardiovascular Risk in Young Finns Study

Oxidative reactions are thought to play a role in the inflammatory condition called fatty liver. It is unclear whether oxidized lipoprotein lipids or proteins are associated with future fatty liver. In the Cardiovascular Risk in Young Finns Study, we determined the circulating levels of LDL and HDL oxidized lipids and studied their associations with fatty liver assessed by ultrasonography. There were 1286 middle-aged subjects with normal liver and 288 subjects with fatty liver. Analysis of oxidized lipids consisted of conjugated dienes in isolated HDL (oxHDLlipids) and LDL (oxLDLlipids). Oxidized LDL was also measured with a method based on antibodies against oxidized apolipoprotein B (oxLDLprot). After adjustment for age, sex, leisure-time physical activity, body mass index, alcohol intake, smoking, serum LDL and HDL cholesterol as well as particle concentrations, participants with elevated oxLDLlipids (odds ratio for 1-SD change in oxLDLlipids = 1.27, p =0.011) had an increased risk for fatty liver. Similarly, a high oxidation score (oxLDLlipids + oxLDLprot) was directly associated with fatty liver (odds ratio=1.34, p = 0.012). The strongest direct association was seen with a high oxLDLlipids/oxHDLlipids ratio (odds ratio=1.49, p = 0.001). These data suggest that oxidized lipoprotein lipids are linked with the risk of fatty liver in middle-aged adults.

The Combined Effect of Common Genetic Risk Variants on Circulating Lipoproteins Is Evident in Childhood: A Longitudinal Analysis of the Cardiovascular Risk in Young Finns Study

Low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG) are modifiable risk factors for cardiovascular disease. Several genetic loci for predisposition to abnormal LDL-C, HDL-C and TG have been identified. However, it remains unclear whether these loci are consistently associated with serum lipid levels at each age or with unique developmental trajectories. Therefore, we assessed the association between genome wide association studies (GWAS) derived polygenic genetic risk scores and LDL-C, HDL-C, and triglyceride trajectories from childhood to adulthood using data available from the 27-year European ‘Cardiovascular Risk in Young Finns’ Study. For 2,442 participants, three weighted genetic risk scores (wGRSs) for HDL-C (38 SNPs), LDL-C (14 SNPs) and triglycerides (24 SNPs) were computed and tested for association with serum lipoprotein levels measured up to 8 times between 1980 and 2011. The categorical analyses revealed no clear divergence of blood lipid trajectories over time between wGRSs categories, with participants in the lower wGRS quartiles tending to have average lipoprotein concentrations 30 to 45% lower than those in the upper-quartile wGRS beginning at age 3 years and continuing through to age 49 years (where the upper-quartile wGRS have 4–7 more risk alleles than the lower wGRS group). Continuous analyses, however, revealed a significant but moderate time-dependent genetic interaction for HDL-C levels, with the association between HDL-C and the continuous HDL-C risk score weakening slightly with age. Conversely, in males, the association between the continuous TG genetic risk score and triglycerides levels tended to be lower in childhood and become more pronounced after the age of 25 years. Although the influence of genetic factors on age-specific lipoprotein values and developmental trajectories is complex, our data show that wGRSs are highly predictive of HDL-C, LDL-C, and triglyceride levels at all ages.

Repeated Blood Pressure Measurements in Childhood in Prediction of Hypertension in Adulthood

Hypertension may be predicted from childhood risk factors. Repeated observations of abnormal blood pressure in childhood may enhance prediction of hypertension and subclinical atherosclerosis in adulthood compared with a single observation. Participants (1927, 54% women) from the Cardiovascular Risk in Young Finns Study had systolic and diastolic blood pressure measurements performed when aged 3 to 24 years. Childhood/youth abnormal blood pressure was defined as above 90th or 95th percentile. After a 21- to 31-year follow-up, at the age of 30 to 45 years, hypertension (>140/90 mm Hg or antihypertensive medication) prevalence was found to be 19%. Carotid intima-media thickness was examined, and high-risk intima-media was defined as intima-media thickness >90th percentile or carotid plaques. Prediction of adulthood hypertension and high-risk intima-media was compared between one observation of abnormal blood pressure in childhood/youth and multiple observations by improved Pearson correlation coefficients and area under the receiver operating curve. When compared with a single measurement, 2 childhood/youth observations improved the correlation for adult systolic (r=0.44 versus 0.35, P<0.001) and diastolic (r=0.35 versus 0.17, P<0.001) blood pressure. In addition, 2 abnormal childhood/youth blood pressure observations increased the prediction of hypertension in adulthood (0.63 for 2 versus 0.60 for 1 observation, P=0.003). When compared with 2 measurements, third observation did not provide any significant improvement for correlation or prediction (P always >0.05). A higher number of childhood/youth observations of abnormal blood pressure did not enhance prediction of adult high-risk intima-media thickness. Compared with a single measurement, the prediction of adult hypertension was enhanced by 2 observations of abnormal blood pressure in childhood/youth.

Increased Body Mass Index in Parent-Child Dyads Predicts the Offspring Risk of Meeting Bariatric Surgery Criteria

CONTEXT

Obesity in children is a major public health concern.

OBJECTIVE

This study examined the value of using parent-child dyads' adiposity status for predicting the individual's later eligibility for bariatric surgery (EBS).

DESIGN, SETTING, AND PARTICIPANTS

The cohort consisted of 2647 individuals from the longitudinal Cardiovascular Risk in Young Finns Study. Baseline information included own and parental body mass index (BMI) in 1980 (children aged 3-18 years), whereas adult follow-up assessment examined EBS 21-31 years later.

MAIN OUTCOME MEASURE

EBS in adulthood was defined as: 1) BMI greater than 40 kg/m(2) or 2) BMI greater than 35 kg/m(2) with at least one of the following metabolic complications: type 2 diabetes, hypertension, or dyslipidemia.

RESULTS

Addition of parents' BMI improved the prediction of adulthood EBS compared to the model including child's BMI, age, and sex (area under the curve values [95% confidence interval] (0.80 [0.74-0.85] vs 0.74 [0.68-0.81], P = .003). Obese children with an obese parent had a 21.2% chance of being EBS in adulthood. Compared to nonobese families, the risk ratio for EBS was 14.2 (95% confidence interval 8.0-25.2, P < .001) in obese children with an obese parent. The absolute risk of EBS was 30.9% if both child and parent were obese on more than one childhood assessment compared to 15.2% if they were obese only once, or 2.1% if they were never obese (P < .05).

CONCLUSIONS

These longitudinal data show that a combination of the child's and parents' BMI at baseline assessment is a useful predictive tool for assessing later EBS, and highlights the importance of accounting for parental BMI in the assessment of child obesity.

Infection-Related Hospitalization in Childhood and Adult Metabolic Outcomes

BACKGROUND AND OBJECTIVES

Identifying childhood determinants of adult cardiometabolic disease would facilitate early-life interventions. There are few longitudinal data on the contribution of childhood infections. Therefore, we investigated whether hospitalization with childhood infection is associated with adult anthropometric and metabolic outcomes in a large, well-phenotyped longitudinal cohort.

METHODS

A total of 1376 subjects from the Cardiovascular Risk in Young Finns Study, aged 3 to 9 years at baseline (1980), who had lifetime data from birth onward on infection-related hospitalization (IRH) had repeated assessments through childhood and adolescence and at least once in adulthood (age 30-45 years in 2001-2011). Early childhood (<5 years), childhood/adolescence (5-18 years), adult (>18 years), and total lifetime IRHs were related to adiposity, BMI, and metabolic syndrome in adulthood. Analyses were adjusted for childhood and adulthood risk factors and potential confounders.

RESULTS

Early-childhood IRH correlated with adverse adult but not childhood metabolic variables: increased BMI (P = .02) and metabolic syndrome (risk ratio: 1.56; 95% confidence interval: 1.03-2.35; P = .03), adjusted for age, gender, birth weight, childhood BMI and other risk factors, and family income. The age at which differences in adult BMI became persistent was related to age of IRH in childhood. The greatest increase in adult BMI occurred in those with >1 childhood IRH.

CONCLUSIONS

Childhood IRH was independently associated with adverse adult metabolic variables. This finding suggests that infections and/or their treatment in childhood may contribute to causal pathways leading to adult cardiometabolic diseases.

Subtle increases in heart size persist into adulthood in growth restricted babies: the Cardiovascular Risk in Young Finns Study

Background and objectives

Impaired fetal growth is associated with increased cardiovascular morbidity and mortality in adulthood. We sought to determine whether adults born with intrauterine growth restriction have primary maladaptive changes in cardiac structure.

Methods

Study participants were adults (34–49 years) who attended the 31-year follow-up of the Cardiovascular Risk in Young Finns Study (longitudinal cohort). Transthoracic echocardiograms and demographic and cardiovascular risk surveys were completed for 157 adults born small for gestational age (SGA, birth weight <10th population centile) and 627 born average for gestational age (average for gestational age (AGA), birth weight 50th–90th population centile).

Results

Those born growth restricted had subtly enlarged hearts with indexed left ventricular (LV) end-systolic and end-diastolic diameters slightly greater in the SGA individuals than the AGA group (LVESD 18.7 mm/m² SGA vs 18.1 mm/m² AGA, p<0.01; LVEDD 27.5 mm/m² SGA vs 26.6 mm/m² AGA, p<0.01); LV base-to-apex length (47.4 mm/m² SGA vs 46.0 mm/m² AGA, p<0.01); LV basal diameter (26.4 mm/m² SGA vs 25.7 mm/m² AGA, p<0.01); and right ventricular base-to-apex length (40.1 mm/m² SGA vs 39.2 mm/m² AGA, p=0.02). LV stroke volume was greater in those born AGA (74.5 mL SGA vs 78.8 mL AGA, p<0.01), with no significant difference in cardiac output (5 L/min SGA vs 5.2 L/min AGA, p=0.06), heart rate, diastolic indices or sphericity index.

Conclusions

Adults born SGA have some statistically significant but subtle changes in cardiac structure and function, which are less marked than have been described in childhood, and are unlikely to play a pathogenic role in their elevated cardiovascular risk.

Longitudinal associations between changes in physical activity and depressive symptoms in adulthood: the young Finns study

BACKGROUND

Although previous studies have associated physical activity (PA) with lower depressive symptoms, the combined effects of the (1) frequency, (2) intensity, and (3) duration of long-term PA have not been examined in detail.

PURPOSE

We examined the dose-response association between changes in frequency, intensity, and duration of PA and depressive symptoms in men and women over 6 years.

METHODS

Participants comprised 1,959 healthy adults (833 men and 1,126 women), aged 24-39 years in 2001, drawn from the ongoing Young Finns Study. PA was assessed using a self-report questionnaire completed in connection with a medical examination in 2001 and 2007. Depressive symptoms were simultaneously assessed using a modified version of Beck's Depression Inventory in both phases.

RESULTS

High doses of PA at baseline were prospectively associated with fewer depressive symptoms in men, while moderate doses of PA at baseline were inversely associated with the prevalence of depressive symptoms in women. Associations between baseline PA and depressive symptom changes were mediated by social and health-related factors which differed between men and women. Long-term participation in regular PA in all dimensions remained remarkably stable (all p < 0.001). Compared to those who remained inactive, the persistently active participants in all dimensions, with the exception of women's intensity group, were more likely to show decreases in depressive symptoms independent of the included confounders. An increase in PA in certain groups was also independently associated with fewer depressive symptoms, particularly in women.

CONCLUSIONS

Regular and persistent participation in different doses of PA may provide short-term and long-term beneficial effects on depressive symptom changes. The results imply that the moderate to high doses of PA may serve as a buffer against depression in early midlife.

The association of dietary alpha-linolenic acid with blood pressure and subclinical atherosclerosis in people born small for gestational age: the Special Turku Coronary Risk Factor Intervention Project study

OBJECTIVE

To determine whether dietary alpha-linolenic (omega-3) fatty acid intake is associated with lower blood pressure and aortic intima-media thickness (IMT) in people born small for gestational age (SGA).

STUDY DESIGN

Participants were recruited at age 6 months and followed up every 6-12 months until age 19 years. Blood pressure and food records were assessed at each visit. A total of 1009 participants had at least one blood pressure measure and complete birth weight and gestational age data, including 115 (11%) born SGA (birth weight≤10th percentile). Aortic IMT was assessed by ultrasound at 19 years (n=413). Analysis was by linear mixed models and multivariable linear regression.

RESULTS

Children born SGA had greater systolic and pulse pressure from age 14 years onwards. In those born SGA, systolic blood pressure was 2.1 mm Hg lower ([95% CI 0.8-3.3]; P=.001) and pulse pressure 1.4 mm Hg lower ([95% CI 0.3-2.4]; P=.01), per exponential increase in alpha-linolenic acid (ALA) intake; weakened by adjustment for anthropometric measures. Long-term ALA intake was inversely associated with aortic IMT at 19 years in those born SGA (-0.30 mm [95% CI -0.52, -0.08] per exponential greater ALA intake; P=.008), independent of other dietary and anthropometric factors.

CONCLUSION

Long-term dietary ALA intake during childhood is associated with improved vascular health in people born SGA.

Determinants of serum 25(OH)D concentration in young and middle-aged adults. The Cardiovascular Risk in Young Finns Study

INTRODUCTION

We studied prevalence of hypovitaminosis D, its determinants, and whether achievement of recommended dietary vitamin D intake (10 μg/d) is associated with absence of hypovitaminosis D in adults.

METHODS

The study is part of the Cardiovascular Risk in Young Finns Study. We collected serum samples of 25-hydroxyvitamin D as part of the 27-year follow-up (994 men and 1,210 women aged 30-45 years). Hypovitaminosis was defined as vitamin D concentration ≤ 50 nmol/L.

RESULTS

Hypovitaminosis D was found in 38% of men and 34% of women. Dietary vitamin D intake (OR 0.90, 95% CI 0.86-0.93), use of vitamin-mineral supplements (0.66, 0.51-0.85), sunny holiday (0.55, 0.41-0.75), and oral contraceptive use in women (0.45, 0.27-0.75) were independently associated with reduced odds of hypovitaminosis. Increase in body mass index (1.06, 1.03-1.09), being a smoker (1.36, 0.97-1.92), investigation month (December versus other) (1.35, 1.12-1.61), and risk alleles in genotypes rs12785878 (1.31, 1.00-1.70) and rs2282679 (2.08, 1.66-2.60) increased odds of hypovitaminosis. Hypovitaminosis D was common also when recommended dietary intake was obtained (men 29%, women 24%).

CONCLUSION

Several factors were associated with hypovitaminosis D. The condition was common even when recommended vitamin D intake was reported. The results support the importance of vitamin D fortification and nutrient supplement use.

Childhood 25-OH vitamin D levels and carotid intima-media thickness in adulthood: the cardiovascular risk in young Finns study

CONTEXT

Low vitamin D levels in adulthood have been associated with cardiovascular disease.

OBJECTIVE

To investigate if low vitamin D levels in childhood are related with increased carotid artery intima-media thickness (IMT) in adulthood.

DESIGN, SETTING, AND PARTICIPANTS

The analyses included 2148 subjects from the Cardiovascular Risk in Young Finns Study, aged 3-18 years at baseline (in 1980). Subjects were re-examined at age 30-45 years (in 2007). Childhood levels of 25-hydroxy-vitamin D were measured from stored serum in 2010.

MAIN OUTCOME MEASURE

The carotid artery IMT from 2007 was used.

RESULTS

When adjusted for age, sex, and childhood risk factors, continuous data of childhood 25-OH vitamin was inversely associated with adulthood carotid IMT levels among females (β ± SE -0.006 ± 0.003, P = 0.03), but not among males (0.001 ± 0.004, P = 0.88). Children with 25-OH vitamin D levels in the lowest quartile (<40 nmol/L) had significantly increased odds of having high-risk IMT (highest decile of common carotid or carotid bulb IMT or carotid plaque) as adults, in analyses adjusted for age, sex and either childhood risk factors (odds ratio 1.70 [95 % CI 1.15-2.31], P = 0.0007) or adult risk factors, including adult vitamin D levels (odds ratio 1.80 [1.30-2.48], P = 0.0004). In sex-specific analyses, these associations were significant both in females and males (P always <0.05). In sensitivity analyses, those with childhood vitamin D levels in the lowest quintile (<37 nmol/L), gave similar results to those using a quartile cut-point.

CONCLUSIONS

Low 25-OH vitamin D levels in childhood were associated with increased carotid IMT in adulthood.

High lipoprotein(a) concentrations are associated with impaired endothelial function in children

OBJECTIVE

To examine the association between familial high lipoprotein(a), or Lp(a), concentrations and endothelial function in children participating in the Special Turku Coronary Risk Factor Intervention Project study.

STUDY DESIGN

Seven-month-old children (n = 1062) with their families were randomized to a risk intervention group or to a control group. The intervention group received individualized dietary counseling to reduce the total cholesterol concentration. Children's Lp(a) and lipid values were measured repeatedly. At age 11 years, children were recruited to an ultrasound study of the flow-mediated dilation (FMD) of the brachial artery. The association between relative peak FMD and Lp(a) concentration was examined in 198 control and 193 intervention group children by linear regression analyses adjusted for sex, total cholesterol concentration, and basal artery diameter. The analyses were made in both the control and intervention groups and in the familial risk children who had a parent with Lp(a) concentration greater than 250 mg/l.

RESULTS

Lp(a) concentrations were similar at age 11 years in the intervention and control groups. In all control children, FMD (%) associated inversely with Lp(a) concentration: (β [%/1000 mg/L] = -3.74, 95% CI [-6.43, -1.45]; P = .007) and in 68 familial risk children (β = -4.92, 95% CI [-8.18, -1.66]; P = .0037). In the intervention group the associations were lacking (P > .5), and FMD in the children with high Lp(a) concentrations (>500 mg/L, n = 12) had no attenuation (P = .027).

CONCLUSIONS

Familial high Lp(a) concentration is associated with attenuated endothelial function. This association may be mitigated by an early lifestyle intervention.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00223600.

Exposure to parental smoking in childhood is associated with increased risk of carotid atherosclerotic plaque in adulthood: the Cardiovascular Risk in Young Finns Study

BACKGROUND

The association between passive smoking exposure in childhood and adverse cardiovascular health in adulthood is not well understood. Using a 26-year follow-up study, we examined whether childhood exposure to passive smoking was associated with carotid atherosclerotic plaque in young adults.

METHODS AND RESULTS

Participants were from the Cardiovascular Risk in Young Finns Study (n=2448). Information on childhood exposure to parental smoking was collected in 1980 and 1983. Carotid ultrasound data were collected in adulthood in 2001 or 2007. Childhood serum cotinine levels from 1980 were measured from frozen samples in 2014 (n=1578). The proportion of children with nondetectable cotinine levels was highest among households in which neither parent smoked (84%), was decreased in households in which 1 parent smoked (62%), and was lowest among households in which both parents smoked (43%). Regardless of adjustment for potential confounding and mediating variables, the relative risk of developing carotid plaque in adulthood increased among those children with 1 or both parents who smoked (relative risk, 1.7; 95% confidence interval, 1.0-2.8; P=0.04). Although children whose parents exercised good "smoking hygiene" (smoking parents whose children had nondetectable cotinine levels) had increased risk of carotid plaque compared with children with nonsmoking parents (relative risk, 1.6; 95% confidence interval, 0.6-4.0; P=0.34), children of smoking parents with poor smoking hygiene (smoking parents whose children had detectable serum cotinine levels) had substantially increased risk of plaque as adults (relative risk, 4.0; 95% confidence interval, 1.7-9.8; P=0.002).

CONCLUSIONS

Children of parents who smoke have increased risk of developing carotid atherosclerotic plaque in adulthood. However, parents who exercise good smoking hygiene can lessen their child's risk of developing plaque.

Adult dyslipidemia prediction is improved by repeated measurements in childhood and young adulthood. The Cardiovascular Risk in Young Finns Study

BACKGROUND

Prediction of adult dyslipidemia has been suggested to improve with multiple measurements in childhood or young adulthood, but there is paucity of specific data from longitudinal studies.

METHODS AND RESULTS

The sample comprised 1912 subjects (54% women) from the Cardiovascular Risk in Young Finns Study who had fasting lipid and lipoprotein measurements collected at three time-points in childhood/young adulthood and had at least one follow-up in later adulthood. Childhood/young adult dyslipidemia was defined as total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non-HDL-C) or triglycerides (TG) in the highest quintile, or high-density lipoprotein cholesterol (HDL-C) in the lowest quintile. Adult dyslipidemia was defined according to European cut-points (TC > 5.0 mmol/L, LDL-C >3 mmol/L, Non-HDL-C >3.8 mmol/L, HDL-C <1.0 mmol/L (in men)/<1.2 mmol/L (in women) and TG > 1.7 mmol/L). With the exception of triglycerides, Pearson correlation coefficients for predicting adult levels significantly improved when two lipid or lipoprotein measurements in childhood/young adulthood were compared with one measurement (all P < 0.01). For triglycerides, there was significant improvement only when three measurements were considered (P = 0.004). Two measurements significantly improved prediction of dyslipidemia levels in adulthood for non-HDL-C, LDL-C, HDL-C and TG compared with one measurement (P < 0.05 for improved area-under the receiver-operating characteristic curve). Risk of dyslipidemia in adulthood grew according to the number of times a person had been at risk in childhood.

CONCLUSIONS

Based on these results, it seems that compared to a single measurement two lipid measures in childhood/early adulthood significantly improve prediction of adult dyslipidemia. A lack of dyslipidemia in childhood does not strongly exclude later development of dyslipidemia. Multiple measurements increase the prediction accuracy, but the incremental prognostic/diagnostic accuracy of especially third measurement is modest.

Prevalence and determinants of fatty liver in normal-weight and overweight young adults. The Cardiovascular Risk in Young Finns Study

BACKGROUND AND AIMS

Fatty liver may have different determinants in normal-weight and in obese individuals. We measured factors associated with fatty liver in 863 normal-weight (BMI < 25) and 1135 overweight/obese (BMI ≥ 25) young and middle-aged adults (45% male, age 34-49 years) in the population-based Cardiovascular Risk in Young Finns Study.

METHODS AND RESULTS

The prevalence of fatty liver detected with ultrasound was 29% in overweight/obese and 5% in normal-weight participants. In overweight/obese, the independent correlates were waist circumference (odds ratio for 1 standard deviation increase = 3.78), alanine transaminase (2.11), BMI (2.00), male sex (1.74), triglycerides (1.44), systolic blood pressure (1.31), fasting insulin (1.23), and physical activity (0.76). In normal weight, the independent correlates included alanine transaminase (3.05), smoking (2.56), systolic blood pressure (1.54), and alcohol intake (1.41). In normal-weight participants, the associations with fatty liver were stronger for alcohol intake and smoking, and weaker for triglycerides, than in overweight/obese participants (P for interaction < 0.05).

CONCLUSION

Prevalence of fatty liver was 29% in overweight/obese and 5% in normal-weight adults. Differences in factors associated with fatty liver were seen between these two groups: alcohol intake and smoking were more strongly and triglycerides more weakly associated in normal-weight than in overweight/obese participants.

Factors associated with six-year weight change in young and middle-aged adults in the Young Finns Study

OBJECTIVE

To examine factors associated with weight change and obesity risk in young and middle-aged adults.

SUBJECTS/METHODS

The Young Finns Study with its 923 women and 792 men aged 24-39 years at baseline were followed for six years. Variables associated with the weight change were investigated with regression models.

RESULTS

The average weight change was 0.45 kg/year in women and 0.58 kg/year in men. In women, weight change was steady across all ages. In men, weight changes were more pronounced in younger age groups. In women (weight gain > 2 kg, n = 490), medication for anxiety, low occupational status, high baseline BMI (body mass index), high intake of sweet beverages, high childhood BMI, high salt (NaCl and/or KCl) use, low number of children, low childhood family income, high stature and low level of dependence (a temperament subscale) were associated with increased weight gain (in the order of importance). In men (weight gain > 2 kg, n = 455), high stature, high intake of french fries, low intake of sweet cookies, young age, recent divorce, low intake of cereals, high intake of milk, depressive symptoms, rural childhood origin, high baseline BMI and unemployment were associated with more pronounced weight gain. Sedentarity (screen-time) was associated with weight gain only in young men. Physical activity and genetic risk for high BMI (score of 31 known variants) were not consistently associated with weight change.

CONCLUSIONS

Socio-economic factors, temperamental and physical characteristics, and some dietary factors are related with weight change in young/middle-aged adults. The weight change occurring in adulthood is also determined by childhood factors, such as high BMI and low family income.

Metabolic syndrome from adolescence to early adulthood: effect of infancy-onset dietary counseling of low saturated fat: the Special Turku Coronary Risk Factor Intervention Project (STRIP)

BACKGROUND

Adolescent metabolic syndrome (MetS) predicts type 2 diabetes mellitus and subclinical atherosclerosis in adulthood. Our aim was to establish the relationship between an infancy-onset dietary intervention and risk of having MetS between 15 and 20 years of age.

METHODS AND RESULTS

The Special Turku Coronary Risk Factor Intervention Project for Children (STRIP) study is a longitudinal, randomized atherosclerosis prevention trial in which repeated dietary counseling aiming at reducing intake of saturated fat took place from infancy to early adulthood. Participants who had complete data on the MetS components (waist circumference, blood pressure, triglycerides, glucose, high-density lipoprotein cholesterol) at 15 (n=512), 16 (n=485), 17 (n=475), 18 (n=459), 19 (n=439), and 20 (n=407) years of age were included in the study. Modified International Diabetes Foundation criteria with 80th/20th percentile cutoff points for the components were primarily applied in statistical analyses, and the results were replicated with the use of other pediatric MetS definitions. Between the ages of 15 and 20 years, the prevalence of MetS varied between 6.0% and 7.5% in participants in the intervention group and between 10% and 14% in the control group. The long-term relative risk of MetS was significantly lower in the intervention group (relative risk, 0.59; 95% confidence interval, 0.40-0.88; P=0.009). Of the individual MetS components, the intervention decreased risk of high blood pressure in both sexes (relative risk, 0.83; 95% confidence interval, 0.70-0.99) and high triglycerides in male subjects (relative risk, 0.71; 95% confidence interval, 0.52-0.98). A statistically nonsignificant reduction was seen in the risk of high waist circumference in the intervention individuals (relative risk, 0.78; 95% confidence interval, 0.59-1.03).

CONCLUSION

Repeated infancy-onset dietary intervention is effective in the prevention of MetS in adolescence.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00223600.

Habitual sleep duration is associated with BMI and macronutrient intake and may be modified by CLOCK genetic variants

BACKGROUND

Short sleep duration has been associated with greater risks of obesity, hypertension, diabetes, and cardiovascular disease. Also, common genetic variants in the human Circadian Locomotor Output Cycles Kaput (CLOCK) show associations with ghrelin and total energy intake.

OBJECTIVES

We examined associations between habitual sleep duration, body mass index (BMI), and macronutrient intake and assessed whether CLOCK variants modify these associations.

DESIGN

We conducted inverse-variance weighted, fixed-effect meta-analyses of results of adjusted associations of sleep duration and BMI and macronutrient intake as percentages of total energy as well as interactions with CLOCK variants from 9 cohort studies including up to 14,906 participants of European descent from the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium.

RESULTS

We observed a significant association between sleep duration and lower BMI (β ± SE = 0.16 ± 0.04, P < 0.0001) in the overall sample; however, associations between sleep duration and relative macronutrient intake were evident in age- and sex-stratified analyses only. We observed a significant association between sleep duration and lower saturated fatty acid intake in younger (aged 20-64 y) adults (men: 0.11 ± 0.06%, P = 0.03; women: 0.10 ± 0.05%, P = 0.04) and with lower carbohydrate (-0.31 ± 0.12%, P < 0.01), higher total fat (0.18 ± 0.09%, P = 0.05), and higher PUFA (0.05 ± 0.02%, P = 0.02) intakes in older (aged 65-80 y) women. In addition, the following 2 nominally significant interactions were observed: between sleep duration and rs12649507 on PUFA intake and between sleep duration and rs6858749 on protein intake.

CONCLUSIONS

Our results indicate that longer habitual sleep duration is associated with lower BMI and age- and sex-specific favorable dietary behaviors. Differences in the relative intake of specific macronutrients associated with short sleep duration could, at least in part, explain previously reported associations between short sleep duration and chronic metabolic abnormalities. In addition, the influence of obesity-associated CLOCK variants on the association between sleep duration and macronutrient intake suggests that longer habitual sleep duration could ameliorate the genetic predisposition to obesity via a favorable dietary profile.

Insulin and BMI as predictors of adult type 2 diabetes mellitus

BACKGROUND AND OBJECTIVES

Fasting insulin concentrations are increasingly being used as a surrogate for insulin resistance and risk for type 2 diabetes (T2DM), although associations with adult outcomes are unclear. Our objective was to determine whether fasting insulin concentrations in childhood associate with later T2DM.

METHODS

Fasting insulin values were available from 2478 participants in the longitudinal Cardiovascular Risk in Young Finns Study at baseline age 3 to 18 years, along with data on adult T2DM (N = 84, mean age = 39.6 years).

RESULTS

Among 3- to 6-year-olds, a 1-SD increase in fasting insulin was associated with a relative risk (RR) of 2.04 (95% confidence interval [CI], 1.54-2.70) for later T2DM, which remained significant after we adjusted for BMI and parental history of T2DM. For those aged 9 to 18 years, a 1-SD increase in insulin was associated with an RR of 1.32 (95% CI, 1.06-1.65) for T2DM, but this became nonsignificant after we adjusted for BMI and parental history of T2DM. In the latter age group, a 1-SD increase in BMI was associated with an RR of 1.45 (95% CI, 1.21-1.73) for T2DM, with adjustment for insulin and parental history of T2DM not improving this association. BMI in younger children was not associated with later T2DM. In life course analyses, those with T2DM had higher fasting insulin levels in early childhood and later adulthood but not in peripubertal years.

CONCLUSIONS

Elevated fasting insulin concentrations in early childhood, but not adolescence, are independently associated with an elevated risk of T2DM in adulthood.

Preconception metabolic indicators predict gestational diabetes and offspring birthweight

Pregnancy conditions such as gestational diabetes (GDM) and macrosomia lead to an increased risk of diabetes and cardiovascular disease in the offspring, perpetuating a cycle of poor health. We hypothesized that (1) pre-pregnancy indicators of metabolism would be associated with GDM and birthweight; and (2) the lipid accumulation product (LAP; incorporating waist circumference and triglycerides) and visceral adiposity index (VAI; incorporating waist circumference, triglycerides, and HDL-c) would be better predictors of GDM and birthweight than other indicators. Data from the Cardiovascular Risk in Young Finns Study were linked to the Finnish birth registry for 349 women. BMI, triglycerides, waist circumference, insulin, HOMA-IR, LAP, and VAI at the visit prior to the pregnancy were examined as predictors of GDM and large-for-gestational-age (LGA) using logistic regression with adjustment for age, parity, and smoking. Waist circumference was the strongest predictor of GDM (adjusted odds ratio [aOR] 1.66, 95% confidence interval 1.16-2.38) and LGA (aOR 1.41, 1.00-1.99). For GDM, all markers had similar discrimination; for LGA, the area under the receiver operating curve for waist circumference was significantly higher than for BMI (p < 0.01). This analysis suggests that pregnancy and even offspring health is affected by risk factors outside the immediate time period of pregnancy.

Exploring causality between TV viewing and weight change in young and middle-aged adults. The Cardiovascular Risk in Young Finns study

BACKGROUND

Television viewing time (TV time) is associated with increased weight and obesity, but it is unclear whether this relation is causal.

METHODS AND RESULTS

We evaluated changes in TV time, waist circumference (waist) and body mass index (BMI) in participants of the population-based Cardiovascular Risk in Young Finns study (761 women, 626 men aged 33-50 years in 2011). Waist and BMI were measured, and TV time was self-reported in 2001, 2007, and 2011. Changes in waist and BMI between 2001 and 2011 were studied a) for the whole group, b) in groups with constantly low (≤ 1 h/d), moderate (1-3 h/d), or high (≥ 3 h/d) TV time, and c) in groups with ≥ 1 hour in-/decrease in daily TV time between 2001 and 2011. BMIs in 1986 were also evaluated. We explored the causal relationship of TV time with waist and BMI by classical temporality criterion and recently introduced causal-discovery algorithms (pairwise causality measures). Both methods supported the hypothesis that TV time is causative to weight gain, and no evidence was found for reverse or bidirectional causality. Constantly low TV time was associated with less pronounced increase in waist and BMI, and waist and BMI increase was lower with decreased TV time (P<0.05). The increase in waist and BMI was at least 2-fold in the high TV time group compared to the low TV time group (P<0.05). Adjustment for age, sex, BMI/waist in 2001, physical activity, energy intake, or smoking did not change the results.

CONCLUSIONS

In young and middle-aged adults, constantly high TV time is temporally antecedent to BMI and waist increase.

Youth overweight and metabolic disturbances in predicting carotid intima-media thickness, type 2 diabetes, and metabolic syndrome in adulthood: the Cardiovascular Risk in Young Finns study

OBJECTIVE

Our objective was to assess cardiovascular risk and metabolic complications in adulthood in subjects with or without overweight and metabolic disturbances (i.e., elevated blood pressure, glucose, triglycerides, low HDL cholesterol, and high LDL cholesterol) and their combinations as youth.

RESEARCH DESIGN AND METHODS

Using data from the population-based Cardiovascular Risk in Young Finns study, we examined the utility of four age- and sex-specific youth phenotypes (group I: normal weight, no metabolic disturbances; group II: normal weight, one or more metabolic disturbances; group III: overweight/obese, no metabolic disturbances; group IV: overweight/obese, one or more metabolic disturbances) in predicting adult high carotid intima-media thickness (IMT), type 2 diabetes mellitus (T2DM), and metabolic syndrome (MetS). The study included 1,617 participants 9-24 years of age at baseline who were followed up 21-25 years later.

RESULTS

IMT (mean ± SEM) was higher among participants in groups II (0.627 ± 0.005 mm, P = 0.05), III (0.647 ± 0.010 mm, P = 0.005), and IV (0.670 ± 0.010 mm, P < 0.0001) compared with group I (0.616 ± 0.003 mm). In addition, subjects in group IV had significantly higher IMT compared with those in group II (P = 0.002). Participants in groups II, III, and IV were at increased risk of the development of MetS in adulthood compared with those in the control group. For group II participants, the difference was attenuated after risk factor adjustments. Additionally, participants in group III and IV were at increased risk of the development of T2DM compared with those in groups I and II.

CONCLUSIONS

While metabolic risk factors associated with overweight increase future risk for MetS, T2DM, and increased IMT, overweight in isolation is also a risk factor. Therefore, overweight should be prevented and treated wherever possible.

Association of physical activity in childhood and early adulthood with carotid artery elasticity 21 years later: the cardiovascular risk in Young Finns Study

BACKGROUND

Decreased arterial elasticity is a risk factor for several cardiovascular outcomes. Longitudinal data on the effect of physical activity in youth on adult arterial elasticity are limited. The aim of this study was to determine the long-term effects of physical activity in children and young adults on carotid artery elasticity after 21 years of follow-up.

METHODS AND RESULTS

Participants were 1417 children (aged 9 to 15 years) and 999 young adults (aged 18 to 24 years) from the prospective Cardiovascular Risk in Young Finns Study. Participants had questionnaire measures of leisure-time physical activity available from 1986 and ultrasound-derived indices of carotid artery elasticity measured in 2007. Carotid artery elasticity indices were distensibility (%/10 mm Hg), Young's elastic modulus (kPa), and stiffness index (unitless). Physical activity at age 18 to 24 years was directly associated with distensibility (β=0.068, P=0.014) and inversely with Young's elastic modulus (β=-0.057, P=0.0037) and indirectly with stiffness index (β=-0.050, P=0.0028) 21 years later in males and females. The associations remained after adjustment for age, sex, body mass index, smoking, systolic blood pressure, serum lipids and insulin, and 21-year change in physical activity. At age 9 to 15 years, the favorable association, remaining after adjustment, was found in males (distensibility [β=0.097, P=0.010], Young's elastic modulus [β=-0.060, P=0.028], and stiffness index [β=-0.062, P=0.007]) but not in females (P=0.70, P=0.85, and P=0.91, respectively).

CONCLUSIONS

Leisure-time physical activity in boys and young adults is associated with carotid artery elasticity later in life, suggesting that higher levels of physical activity in youth may benefit future cardiovascular health.