Commuting physical activity is favourably associated with biological risk factors for cardiovascular disease

Association Between Domain-Specific Physical Activity and Cardiometabolic Factors in a Multiethnic Asian Population: A Longitudinal Study

AIMS

To examine the association between domain-specific physical activity (PA) and cardiometabolic factors with longitudinal data, which is limited in current literature.

METHODS

Participants who attended the Singapore Multi-Ethnic Cohort and follow-up surveys were included in this study (N = 3950, mean age: 44.7 y, female: 57.9%). Self-reported moderate- to vigorous-intensity PA (MVPA) for each domain (leisure-time, transportation, occupation, and household) was categorized into 4 levels: no, low, middle, and high MVPA. The longitudinal associations of domain-specific MVPA with cardiometabolic factors including systolic and diastolic blood pressures, low-density and high-density lipoprotein cholesterols, triglycerides, and body mass index were examined using Generalized Estimating Equations, accounting for confounding factors and repeated measurements.

RESULTS

There were 5.2% participants who had no MVPA. For each domain, this rate ranged from 22.6% (household) to 83.3% (occupation). Leisure-time and occupation MVPAs had positive and linear associations with high-density lipoprotein cholesterols, corresponding to 0.030 (95% confidence interval, 0.015 to 0.045) mmol/L (leisure-time) and 0.063 (95% confidence interval, 0.043 to 0.083) mmol/L (occupation), when compared high with no respective MVPA. Occupation and household MVPAs were associated with low-density lipoprotein cholesterol. Transportation and occupation exhibited a positive and linear relationship with diastolic blood pressure. None of the domains were associated with body mass index, systolic blood pressures, or triglycerides.

CONCLUSIONS

This study showed that each domain had differential association with individual cardiometabolic risk factors. As occupation, transportation, or household PA had unfavorable associations with low-density lipoprotein cholesterol or diastolic blood pressure, the overall beneficial impact of higher PA levels may not necessarily hold in the context of domain-specific PA and cardiovascular health. Further investigation is needed to corroborate our findings.

Non-linear interaction between physical activity and polygenic risk score of body mass index in Danish and Russian populations

Body mass index (BMI) is a highly heritable polygenic trait. It is also affected by various environmental and behavioral risk factors. We used a BMI polygenic risk score (PRS) to study the interplay between the genetic and environmental factors defining BMI. First, we generated a BMI PRS that explained more variance than a BMI genetic risk score (GRS), which was using only genome-wide significant BMI-associated variants (R² = 13.1% compared to 6.1%). Second, we analyzed interactions between BMI PRS and seven environmental factors. We found a significant interaction between physical activity and BMI PRS, even when the well-known effect of the FTO region was excluded from the PRS, using a small dataset of 6,179 samples. Third, we stratified the study population into two risk groups using BMI PRS. The top 22% of the studied populations were included in a high PRS risk group. Engagement in self-reported physical activity was associated with a 1.66 kg/m² decrease in BMI in this group, compared to a 0.84 kg/m² decrease in BMI in the rest of the population. Our results (i) confirm that genetic background strongly affects adult BMI in the general population, (ii) show a non-linear interaction between BMI genetics and physical activity, and (iii) provide a standardized framework for future gene-environment interaction analyses.

Device-Measured and Self-Reported Active Travel Associations with Cardiovascular Disease Risk Factors in an Ethnically Diverse Sample of Adults

Active travel (AT) provides an opportunity to alleviate the physical inactivity and climate crises contributing to the global chronic disease burden, including cardiovascular diseases (CVD). Though AT shows promising links to reduced CVD risk, prior studies relied on self-reported AT assessment. In the present study, device-measured and self-reported AT were compared across population subgroups and relationships with CVD risk biomarkers were evaluated for both measures. The study recruited an ethnically diverse sample (N = 602, mean age 59 years, 42% Hispanic/Latino ethnicity) from neighborhoods that varied by walkability and food access. AT was assessed using concurrently collected accelerometer and GPS data and self-report data from a validated survey. Relationships with body mass index (BMI), triglycerides, high-density lipoprotein (HDL) cholesterol, blood pressure (BP), and moderate-to-vigorous physical activity (MVPA) were modeled using multivariable linear regression. Devices captured more AT than did self-report. We found differences in AT measures by population subgroups, including race, ethnicity, education, income, vehicle access, and walkability. Men had more accelerometer-measured MVPA, though women self-reported more daily minutes. Both device and survey AT measures were positively associated with total accelerometer-measured MVPA, though the relationship was stronger with device-measured AT. Device-measured AT was associated with lower BMI. No other CVD risk biomarker was associated with either AT measure. No effect modification by Hispanic/Latino ethnicity was detected. Further studies with device-based measures are warranted to better understand the relationship between AT and cardiovascular health.

Association between physical activity and sickness absenteeism in university workers

BACKGROUND

Sedentary occupations have increased by more than 10% in Western countries over the last two decades, and the yearly global cost of physical inactivity has been estimated to be $53.8 billion. As workers tend to move less in the workplace, they are more likely to develop a sedentarism-related chronic condition and to be absent from work due to illness, although research evidence on the issue remains unclear.

AIMS

To investigate associations between physical activity (PA) and sickness absenteeism in the workplace among Spanish university workers.

METHODS

We conducted cross-sectional research with data from 1025 workers aged 18-65 years (43% women) from a Spanish university. Physical Activity Vital Sign (PAVS) and International Physical Activity Questionnaire (IPAQ) short versions were used to evaluate levels of PA. Workplace absenteeism was self-reported by participants. Written questionnaires distributed during medical checks included PAVS, IPAQ and the question about absenteeism among other information. The association between PA and sickness absenteeism was examined using adjusted multiple linear regression.

RESULTS

After adjusting for age, sex, job function, chronic conditions, sedentarism and smoking, each weekly hour of PA reduced sickness absence by -1.20 (95% confidence interval: -2.40-0.00) days per year.

CONCLUSIONS

The implementation of PA promotion strategies aimed at university employees may lead to a reduction of days off work due to illness.

Soluble urokinase plasminogen activator receptor is linearly associated with dietary quality and predicts mortality

Chronic inflammation is associated with disease risk and mortality in the general population. Soluble urokinase plasminogen activator receptor (suPAR) is a stable marker of chronic inflammation, and a higher serum-concentration of suPAR is found in individuals with an unhealthy lifestyle such as smoking. This article investigates the association between suPAR and dietary quality measured with the dietary quality score (DQS). The DQS is an index of the overall quality of an individual's dietary habits assessed through a self-administered FFQ. Furthermore, this article investigates the association of both suPAR and the DQS with CVD risk and mortality in the general Danish population. We analysed 5347 individuals aged 30-60 years from the Danish Inter99 study cohort. Multiple linear regression analyses showed a linear inverse association between the DQS and suPAR (P=0·0005). Cox regression analyses showed an 18 (95 % CI 9, 26) % increase in the risk of death from any cause with each 1 ng/ml increase in suPAR. We found no significant association between the DQS and the mortality (hazard ratio: 1·16, 95 % CI 0·79, 1·69). All analyses were adjusted for demographics and lifestyle factors. The association between the DQS and suPAR on the one hand and suPAR and mortality on the other supports the argument that low dietary quality may constitute a health risk through its influence on chronic inflammation. Future research should examine whether suPAR is modifiable through changes in dietary habits.

Population-based studies of relationships between dietary acidity load, insulin resistance and incident diabetes in Danes

BACKGROUND

It has been suggested that the acidity of the diet may be related to increased risk of type 2 diabetes. To investigate this hypothesis, we tested if the acidity of the diet, measured as the Potential Renal Acid Load (PRAL) score, was associated with incident diabetes and diabetes-related intermediary traits.

METHODS

A total of 54,651 individuals from the Danish Diet, Cancer and Health (DCH) cohort were included in the prospective cox regression analyses of incident diabetes over a 15 years follow-up period. Moreover, 5724 Danish individuals with baseline data from the Inter99 cohort were included in the cross sectional, multivariate and logistic regression analyses of measures of insulin sensitivity, insulin release and glucose tolerance status derived from an oral glucose tolerance test (OGTT).

RESULTS

In the DCH cohort a trend analysis showed that quintiles of PRAL score were, after multifactorial adjustment, associated with a higher incidence of diabetes (p_trend = 6 × 10^- 7). HR for incident diabetes was 1.24 (1.14; 1.35) (p = 7 × 10^- 7) between first and fifth PRAL score quintile. In Inter99 higher PRAL score associated with insulin resistance as estimated by lower BIGTT-Si (an OGTT-derived index of insulin sensitivity) (p = 4 × 10^- 7) and Matsuda index of insulin sensitivity (p = 2 × 10^- 5) as well as higher HOMA-IR (p = 0.001). No association was observed for measures of insulin release, but higher PRAL score was associated with lower OGTT-based disposition index.

CONCLUSIONS

A high dietary acidity load is associated with a higher risk of diabetes among middle-aged Danes. Although adjustment for BMI attenuated the effect sizes the association remained significant. The increased risk of diabetes may be related to our finding that a high dietary acidity load associates with impaired insulin sensitivity.

What Factors Explain Bicycling and Walking for Commuting by ELSA-Brasil Participants?

Purpose:

To analyze the factors associated with commuting by bicycling and walking in adult participants from ELSA-Brasil (Longitudinal Study of Adult Health).

Design:

Cross-sectional.

Setting:

Six teaching/research institutions throughout Brazil.

Participants:

A total of 15 105 civil servants.

Measures:

Commuting by bicycling and walking was analyzed using the long-form International Physical Activity Questionnaire.

Analysis:

A hierarchical model containing possible factors associated with commuting by bicycling and walking was constructed. Crude and adjusted odds ratios were calculated using multinomial logistic regression.

Results:

Considering the 2 forms of commuting, 66% of the participants were being considered inactive or insufficiently active. In women, being “heavier,” feeling unsafe practicing physical activity, and being a former smoker were factors negatively associated with commuting by bicycling and walking. In men, active commuting was less common among those who were overweight or had abdominal obesity, those with a negative perception of safety, and those reporting that there was nowhere suitable in the neighborhood to practice physical activity.

Conclusion:

Obesity and negative perceptions in the neighborhood are associated with inactive or insufficiently active commuting. The relevance of this finding for public health is reinforce developing policies aimed at promoting health in Brazil and in other countries with similar characteristics.

Genetic determinants of serum vitamin B12 and their relation to body mass index

Lower serum vitamin B12 levels have been related to adverse metabolic health profiles, including adiposity. We used a Mendelian randomization design to test whether this relation might be causal. We included two Danish population-based studies (ntotal = 9311). Linear regression was used to test for associations between (1) serum vitamin B12 levels and body mass index (BMI), (2) genetic variants and serum vitamin B12 levels, and (3) genetic variants and BMI. The effect of a genetically determined decrease in serum vitamin B12 on BMI was estimated by instrumental variable regression. Decreased serum vitamin B12 associated with increased BMI (P < 1 × 10-4). A genetic risk score based on eight vitamin B12 associated variants associated strongly with serum vitamin B12 (P < 2 × 10-43), but not with BMI (P = 0.91). Instrumental variable regression showed that a 20% decrease in serum vitamin B12 was associated with a 0.09 kg/m2 (95% CI 0.05; 0.13) increase in BMI (P = 3 × 10-5), whereas a genetically induced 20% decrease in serum vitamin B12 had no effect on BMI [-0.03 (95% CI -0.22; 0.16) kg/m2] (P = 0.74). Nevertheless, the strongest serum vitamin B12 variant, FUT2 rs602662, which was excluded from the B12 genetic risk score due to potential pleiotropic effects, showed a per allele effect of 0.15 kg/m2 (95% CI 0.01; 0.32) on BMI (P = 0.03). This association was accentuated including two German cohorts (ntotal = 5050), with a combined effect of 0.19 kg/m2 (95% CI 0.08; 0.30) (P = 4 × 10-4). We found no support for a causal role of decreased serum vitamin B12 levels in obesity. However, our study suggests that FUT2, through its regulation of the cross-talk between gut microbes and the human host, might explain a part of the observational association between serum vitamin B12 and BMI.

Increasing insulin resistance accentuates the effect of triglyceride-associated loci on serum triglycerides during 5 years

Blood concentrations of triglycerides are influenced by genetic factors as well as a number of environmental factors, including adiposity and glucose homeostasis. The aim was to investigate the association between a serum triglyceride weighted genetic risk score (wGRS) and changes in fasting serum triglyceride level over 5 years and to test whether the effect of the wGRS was modified by 5 year changes of adiposity, insulin resistance, and lifestyle factors. A total of 3,474 nondiabetic individuals from the Danish Inter99 cohort participated in both the baseline and 5 year follow-up physical examinations and had information on the wGRS comprising 39 genetic variants. In a linear regression model adjusted for age, sex, and baseline serum triglyceride, the wGRS was associated with increased serum triglyceride levels over 5 years [per allele effect = 1.3% (1.0-1.6%); P = 1.0 × 10-17]. This triglyceride-increasing effect of the wGRS interacted with changes in insulin resistance (Pinteraction = 1.5 × 10-6). This interaction indicated that the effect of the wGRS was stronger in individuals who became more insulin resistant over 5 years. In conclusion, our findings suggest that increased genetic risk load is associated with a larger increase in fasting serum triglyceride levels in nondiabetic individuals during 5 years of follow-up. This effect of the wGRS is accentuated by increasing insulin resistance.

The relationship between utilitarian walking, utilitarian cycling, and body mass index in a population based cohort study of adults: comparing random intercepts and fixed effects models

OBJECTIVE

To examine associations between utilitarian walking, utilitarian cycling, leisure time physical activity and body mass index (BMI).

METHODS

Participants from the National Population Health Survey (NPHS) of Statistics Canada were interviewed by telephone every two years from 1994 to 2010. Analysis includes data from 6894 living participants aged 18-64years. Fixed effects and random intercepts models examined the association between BMI, utilitarian walking, and utilitarian cycling, controlling for behavioral and sociodemographic factors.

RESULTS

The final adjusted fixed effects models showed no significant relationship between utilitarian walking and BMI. In the unbalanced sample utilitarian cycling for 1 to 5h per week (b=-0.15, 95% CI: -0.28 to -0.02), and more than 5h per week (b=-0.22, 95% CI: -0.44 to 0.00) was significantly associated with BMI over time. In the fully balanced sample utilitarian cycling for 1 to 5h per week (b=-0.12, 95% CI: -0.27 to 0.03), more than 5h per week (b=-0.16, 95% CI: -0.45 to 0.13) was not significantly associated with BMI over time.

CONCLUSION

The results suggest that utilitarian walking is not related to BMI. The relationship between utilitarian cycling and BMI is less clear.

Impact of size at birth and prematurity on adult anthropometry in 4744 middle-aged Danes - The Inter99 study

Low birth weight is related to increased risk of developing cardiovascular disease and type 2 diabetes in adult life. Since obesity is closely associated with type 2 diabetes and cardiovascular disease, the relationship between size at birth and adult anthropometry is of interest as a mediator of the relationship between birth weight and metabolic diseases. The aim of this study was, therefore, to examine the effect of size at birth and prematurity on measures of adult anthropometry taking adult socio-economic status and lifestyle variables into account. Midwife records with information on mother's age and parity as well as weight, length and maturity at birth were traced in 4744 Danes born between 1939 and 1970. Measures of adult anthropometry (weight, height, body mass index (BMI), waist circumference, hip circumference and waist/hip ratio) had previously been recorded together with information on socio-economic factors, lifestyle and parental diabetes status. Mother's age, parity and diabetes status were associated with offspring birth weight. Size at birth was positively associated with adult height and weight, but only weakly associated with BMI and not associated with waist/hip ratio when adjusted for socio-economic and lifestyle factors. Infants born preterm were less growth restricted at birth and grew to be taller and heavier compared with term infants born small for gestational age. Altogether, this study does not find evidence that obesity or a central fat distribution is mediating the relationship between low birth weight and risk of cardiovascular disease or type 2 diabetes in later life.

Dejavniki gibalne aktivnosti in z zdravjem povezane kakovosti življenja

Uvod: Gibalna aktivnost koristi telesnemu in duševnemu zdravju. Namen članka je ugotoviti dejavnike, ki vplivajo nanjo, in možne ukrepe za povečanje te dejavnosti. Cilj članka je spodbuditi strokovnjake s področij zdravja in športne dejavnosti k sodelovanju pri oblikovanju in izvajanju učinkovitih ukrepov za povečanje gibanja med prebivalstvom. Metode: Opravljen je bil pregled literature o dejavnikih, ki vplivajo na gibalno aktivnost in z zdravjem povezano kakovost življenja, ter o ukrepih, povezanih z njimi. V pregled so vključene raziskave, ki so objavljene v angleškem jeziku v obdobju 2000–2010 in evidentirane v Web of Science (SCI-EXPANDED ali SSCI). Članek povzema izsledke 46 objav, za potrebe teoretičnih izhodišč pa še dodatnih 43 objav. Rezultati: Na odločitev za gibanje vplivajo lastnosti posameznika in širšega družbenoekonomskega okolja. Bistveni so starost, spol in zdravstveni status posameznika. Pri posameznih skupinah populacije prepoznamo specifične dejavnike, ki vplivajo na odločitev za gibalno aktivnost. Učinkoviti ukrepi spodbujanja gibanja so zato usmerjeni na te skupine in izhajajo iz identificiranih dejavnikov. Diskusija in zaključek: Raznolikost omenjenih skupin in dejavnikov je osnova za načrtovanje preventivnih oziroma interventnih ukrepov. Smiselno je, da se pri organiziranju in izvajanju programov povežejo organizacije s področij zdravstva, športa in druge interesne skupine. Pri tem naj izkoristijo obstoječe zakonske okvire.

The effect of GWAS identified BMI loci on changes in body weight among middle-aged Danes during a five-year period

OBJECTIVE

Genome-wide association studies have identified genetic variants associating with BMI, however, it is un-clarified whether the same variants also influence body weight fluctuations.

METHODS

Among 3,982 adult individuals that attended both a baseline and a five-year follow-up examination in the Danish Inter99 intervention study, a genetic risk score (GRS) was constructed based on 30 BMI variants to address whether it is associated with body weight changes. Moreover, it was examined whether the effect of lifestyle changes was modulated by the GRS.

RESULTS

The GRS associated strongly with baseline body weight, with a per risk allele increase of 0.45 (0.33-0.58) kg (P = 2.7 × 10(-12) ), corresponding to a body weight difference of 3.41 (2.21-4.60) kg comparing the highest (≥ 30 risk alleles) and lowest (≤ 26 risk alleles) risk allele tertile. No association was observed with changes in body weight during the five years. Changes in lifestyle, including physical activity, diet and smoking habits associated strongly with body weight changes, however, no interactions with the GRS was observed.

CONCLUSION

The GRS associated with body weight cross-sectionally, but not with changes over a five-year period. Body weight changes were influenced by lifestyle changes, however, independently of the GRS.

Genetic risk score of 46 type 2 diabetes risk variants associates with changes in plasma glucose and estimates of pancreatic β-cell function over 5 years of follow-up

More than 40 genetic risk variants for type 2 diabetes have been validated. We aimed to test whether a genetic risk score associates with the incidence of type 2 diabetes and with 5-year changes in glycemic traits and whether the effects were modulated by changes in BMI and lifestyle. The Inter99 study population was genotyped for 46 variants, and a genetic risk score was constructed. During a median follow-up of 11 years, 327 of 5,850 individuals developed diabetes. Physical examinations and oral glucose tolerance tests were performed at baseline and after 5 years (n = 3,727). The risk of incident type 2 diabetes was increased with a hazard ratio of 1.06 (95% CI 1.03-1.08) per risk allele. While the population in general had improved glucose regulation during the 5-year follow-up period, each additional allele in the genetic risk score was associated with a relative increase in fasting, 30-min, and 120-min plasma glucose values and a relative decrease in measures of β-cell function over the 5-year period, whereas indices of insulin sensitivity were unaffected. The effect of the genetic risk score on 5-year changes in fasting plasma glucose was stronger in individuals who increased their BMI. In conclusion, a genetic risk score based on 46 variants associated strongly with incident type 2 diabetes and 5-year changes in plasma glucose and β-cell function. Individuals who gain weight may be more susceptible to the cumulative impact of type 2 diabetes risk variants on fasting plasma glucose.

Dairy product intake in relation to glucose regulation indices and risk of type 2 diabetes

BACKGROUND AND AIM

A high intake of dairy has been linked to lower risk of type 2 diabetes (T2D). The relationship between dairy intake and glucose metabolism is still not well understood. The aim of this study was to investigate the relation between the intake of total dairy and dairy subgroups and T2D and measures of glucose metabolism.

METHODS AND RESULTS

A total of 5953 Danish men and women aged 30-60 years without baseline diabetes or cardiovascular diseases were included in this prospective analysis. The dairy intake at baseline was categorised into low-fat dairy, full-fat dairy, milk and milk products, cheese and fermented dairy. Fasting plasma glucose (FPG), 2-h plasma glucose (2hPG), HbA1c, insulin resistance (HOMA2-IR) and beta-cell function (HOMA2-B) were considered at 5-year follow-up. In the maximally-adjusted model (demographics, lifestyle factors, dietary factors and waist), cheese intake was inversely associated with 2hPG (β = -0.048, 95% CI -0.095; -0.001). Fermented dairy intake was inversely associated with FPG (β = -0.028, 95% CI -0.048; -0.008) and HbA1c (β = -0.016, 95% CI -0.030; -0.001). Total dairy intake and the dairy subgroups were not related to HOMA-IR and HOMA-B in the maximally-adjusted model. Furthermore, there was no significant association between intake of total dairy or any of the dairy subgroups and incidence of T2D.

CONCLUSION

Our data suggest a modest beneficial effect of cheese and fermented dairy on glucose regulation measures; however, this did not translate into a significant association with incident T2D.

The potential modal shift and health benefits of implementing a public bicycle share program in Montreal, Canada

BACKGROUND

This study estimated the modal shift associated with the implementation of a public bicycle share program in Montreal, Canada.

METHODS

A population-based sample of adults participated in two cross sectional telephone surveys. Self-reported travel behaviors were collected at the end of the first (fall 2009) and second (fall 2010) season of implementation. The sample included 2502 (Mean age=47.8 years, 61.8% female), and 2509 (Mean age=48.9 years, 59.0% female) adult respondents in each survey.

RESULTS

The estimated modal shift associated with the implementation of the PBSP from motor vehicle use to walking, cycling, and public transportation was 6483 and 8023 trips in 2009 and 2010. This change represents 0.34% and 0.43% of all motor vehicle trips in Montreal.

CONCLUSIONS

The implementation of a PBSP was associated with a shift toward active transportation. The modal shift was complex and not simply the result of a discrete shift from one mode to another. Promotion of active transportation should encourage integration of multiple active transportation modes to better reflect people's actual transportation behaviors.

Impact evaluation of a public bicycle share program on cycling: a case example of BIXI in Montreal, Quebec

OBJECTIVES

We examined associations between residential exposure to BIXI (BIcycle-taXI)-a public bicycle share program implemented in Montreal, Quebec, in 2009, which increases accessibility to cycling by making available 5050 bicycles at 405 bicycle docking stations-and likelihood of cycling (BIXI and non-BIXI) in Montreal over the first 2 years of implementation.

METHODS

Three population-based samples of adults participated in telephone surveys. Data collection occurred at the launch of the program (spring 2009), and at the end of the first (fall 2009) and second (fall 2010) seasons of implementation. Difference in differences models assessed whether greater cycling was observed for those exposed to BIXI compared with those not exposed at each time point.

RESULTS

We observed a greater likelihood of cycling for those exposed to the public bicycle share program after the second season of implementation (odds ratio = 2.86; 95% confidence interval = 1.85, 4.42) after we controlled for weather, built environment, and individual variables.

CONCLUSIONS

The implementation of a public bicycle share program can lead to greater likelihood of cycling among persons living in areas where bicycles are made available.

The relationship between changes in health behaviour and initiation of lipid-lowering and antihypertensive medications in individuals at high risk of ischaemic heart disease

BACKGROUND

It has been hypothesised that health conscious individuals tend to take better care of themselves by greater adherence to preventive medications. We examined, whether long-term changes in dietary habits and physical activity were associated with initiation of lipid-lowering and antihypertensive medications.

METHODS

The study population consisted of two subsamples from the population-based cohort Inter99 study (1999-2006) in Copenhagen, Denmark: one with systolic blood pressure > 140 mmHg (N = 557) and one with total cholesterol > 7 mmol/L (N = 314). At a health examination, individuals completed a questionnaire about health behaviour and had their blood pressure and cholesterol measured at baseline and after five years. Data on medications were obtained through linkage to the Registry of Medical Product Statistics.

RESULTS

Positive changes in physical activity (odds ratio =3.50; 95% CI 1.23-7.54) and in dietary habits (odds ratio = 2.08; 95% CI 1.03-4.21) were associated with an increased initiation of lipid-lowering medications. With respect to antihypertensives, no association was observed in terms of physical activity, but for diet, a positive trend in terms of initiation was observed among those with positive changes in dietary habits (odds ratio = 1.58; 95% CI 0.96-2.59).

CONCLUSION

Generally, we observed health conscious behaviour in terms of increased initiation of preventive medications among those who reported positive changes in health behaviour. This study therefore suggests that more attention should be given to identifying individuals and groups, who are less health conscious and thereby less likely to engage in either preventive medications or changes in health behaviours.

Active transport, physical activity, and body weight in adults: a systematic review

CONTEXT

Physical activity has various health benefits. Active transport can contribute to total physical activity and thus affect body weight because of increased energy expenditure. This review summarizes published evidence on associations of active transport, general physical activity, and body weight in adults.

EVIDENCE ACQUISITION

A systematic review of the literature was conducted in October 2010 using eight databases. A total of 14,216 references were screened; full texts were retrieved for 95 articles. Forty-six articles (36 unique studies) were included: 20 (17) from Europe; 18 (13) from North America, Australia, and New Zealand; and eight (six) from other countries. Analyses of the retrieved papers were carried out between November 2010 and March 2011.

EVIDENCE SYNTHESIS

Of 15 studies assessing active transport and physical activity, five found associations in the expected direction (more active transport associated with more physical activity) for all or most variables studied, nine found some associations, and one reported no associations. Of 30 studies assessing active transport and body weight, 13 reported associations in the expected direction (more active transport associated with lower body weight) for all or most variables studied, 12 found some associations, two presented some associations in the expected and some in the opposite direction, and three reported no associations.

CONCLUSIONS

There is limited evidence that active transport is associated with more physical activity as well as lower body weight in adults. However, study heterogeneity, predominantly cross-sectional designs, and crude measures for active transport and physical activity impede quantitative conclusions.

The impact of public transportation strikes on use of a bicycle share program in London: interrupted time series design

OBJECTIVE

To investigate the immediate and sustained effects of two London Underground strikes on use of a public bicycle share program.

METHODS

An interrupted time series design was used to examine the impact of two 24 hour strikes on the total number of trips per day and mean trip duration per day on the London public bicycle share program. The strikes occurred on September 6th and October 4th 2010 and limited service on the London Underground.

RESULTS

The mean total number of trips per day over the whole study period was 14,699 (SD=5390) while the mean trip duration was 18.5 minutes (SD=3.7). Significant increases in daily trip count were observed following strike 1 (3864: 95% CI 125 to 7604) and strike 2 (11,293: 95% CI 5169 to 17,416).

CONCLUSIONS

Events that greatly constrain the primary motorised mode of transportation for a population may have unintended short-term effects on travel behaviour. These findings suggest that limiting transportation options may have the potential to increase population levels of physical activity by promoting the use of cycling.

Associations between physical activity and physical and mental health--a HUNT 3 study

PURPOSE

Health-related quality of life (HRQoL) has been characterized as the ultimate goal for health interventions such as physical activity (PA). We assessed how frequency, duration, and intensity of PA were related to HRQoL in younger (<65 yr) and older (≥65 yr) females and males.

METHODS

This population-based cross-sectional study explored associations between frequency, duration, and intensity of PA and physical and mental health. HRQoL was measured by SF-8 Health Survey. Frequency and duration were assessed by items validated in a previous HUNT study, and intensity was assessed by Borg RPE scale. Associations between PA and physical and mental health were estimated using general linear modeling.

RESULTS

A total of 4500 participants (56% females), age 19-91 yr, with mean age of 53±15 yr, were included. Of these, 40% were less active than recommended by international guidelines. In general, mean physical health (PCS-8) in females and males was 47.4±9.7 and 48.8±8.9, and mental health (MCS-8) was 50.5±8.0 and 51.9±7.3, respectively. Age-adjusted association between PA and HRQoL was stronger for physical than mental health in both genders and age groups. The largest differences were between no exercise and exercise groups at any level for frequency, duration, and intensity of PA. We found no substantial gender differences in association between PA and HRQoL, but association was stronger in older (≥65 yr) than younger (<65 yr) females and males. Adjusting for socioeconomic factors and factors such as presence of diseases, body mass index, smoking habits, cohabitation, and disablement did not change the results.

CONCLUSIONS

The study suggests that exercising at any level is associated with better physical and mental health in both genders compared with no exercise, particularly among the older individuals.

The effects of adding group-based lifestyle counselling to individual counselling on changes in plasma glucose levels in a randomized controlled trial: the Inter99 study

AIM

This study aimed to assess whether group-based lifestyle counselling offered to a high-risk population subgroup had any effect beyond individual multifactorial interventions on fasting plasma glucose (FPG) and 2-h plasma glucose (2hPG) changes.

METHODS

In a population-based study of 6784 participants, 4053 were determined to be at high risk based on a risk estimate of ischaemic heart disease or the presence of risk factors (smoking, hypertension, hypercholesterolaemia, obesity, impaired glucose tolerance). Of these subjects, 90% were randomized to high-intensity intervention (group A) and 10% to low-intensity intervention (group B). All participants went through health examinations, risk assessments and individual lifestyle counselling. Participants in group A were further offered group-based lifestyle counselling. The intervention was repeated after 1 and 3 years. A total of 2738 participants free of diabetes at baseline (1999-2001) and with at least one FPG and/or 2hPG measurement during 5 years of follow-up were included in the analyses. Differences in changes of plasma glucose between groups A and B were analyzed using multilevel linear regression.

RESULTS

For FPG, crude 5-year changes were significantly different between the two groups (group A: -0.003 mmol/L vs group B: -0.079 mmol/L; P=0.0427). After adjusting for relevant confounders, no differences in FPG changes were observed (P=0.116). Also, no significant differences in the 5-year changes in 2hPG between the two groups were observed (group A: - 0.127 mmol/L vs group B: -0.201 mmol/L; P=0.546).

CONCLUSION

Offering additional group-based intervention to a high-risk population subgroup had no clinical effects on changes in plasma glucose beyond those of individualized multifactorial interventions.

Commuting physical activity and prevalence of metabolic disorders in Poland

OBJECTIVES

The aim of this study was to examine the relationship between walking or cycling to work and prevalence of metabolic syndrome (MetS) and its components.

METHODS

Cross-sectional analysis of 6401 randomly selected individuals (3297 men and 3104 women) aged 20-74 years, who participated in the National Multicentre Health Survey WOBASZ, Poland (2002-2005). Commuting physical activity (PA) was assessed by asking about type and time spent on transportation to/from work using an interviewer-administered questionnaire. Weight, height, waist circumference (WC), blood pressure (BP), fasting plasma glucose (FPG), triglycerides (TG) and high-density cholesterol, (HDL-C) were measured by standard methods. MetS was defined according to the NCEP-ATP III and IDF criteria.

RESULTS

Active commuting was associated with decreased likelihood of abdominal obesity (WC≥94 cm), lower HDL-C and elevated TG in men and abdominal obesity (WC≥80 cm) in women. In a subgroup of postmenopausal women (n=317) active commuting was favourably associated with abdominal obesity, low HDL-C and elevated FPG. Prevalence of MetS was significantly lower among those who spent above 30 min/day daily on walking/cycling to work than among other gender subgroups.

CONCLUSION

Increasing of commuting PA level may have an important influence on reducing the prevalence of metabolic disorders.

Walking: the first steps in cardiovascular disease prevention

PURPOSE OF REVIEW

Health professionals are presented with the challenge of prescribing physical activity that is likely to be sustained by the sedentary majority. Walking is eminently suited to physical activity prescription for inactive individuals as it is accessible to men and women of all ages and social groups and poses little risk of injury. This paper reviews recent evidence of the health benefits of walking and promotion of walking behavior.

RECENT FINDINGS

Large observational studies consistently show associations between walking and cardiovascular disease endpoints over long periods of follow-up. Intervention studies further support the health benefits of walking, showing improvements in clinical biomarkers and measures after shorter periods of follow-up. Walking appears to have cardiovascular disease-related health benefits in younger, middle-aged, and older men and women, in both healthy and patient populations. Pedometer-based, mobile phone-based, and computer-based programs are effective in increasing walking levels. Neighborhood and workplace amenities and programs may be important supports for walking behaviors.

SUMMARY

Walking has the potential to play a key role in the primary and secondary prevention of cardiovascular disease. Clinicians can prescribe walking to assist patients meet physical activity recommendations and help identify supports available to the patient.

The association of alcohol and alcohol metabolizing gene variants with diabetes and coronary heart disease risk factors in a white population

BACKGROUND

Epidemiological studies have shown a J- or U-shaped relation between alcohol and type 2 diabetes and coronary heart disease (CHD). The underlying mechanisms are not clear. The aim was to examine the association between alcohol intake and diabetes and intermediate CHD risk factors in relation to selected ADH and ALDH gene variants.

METHODOLOGY/PRINCIPAL FINDINGS

Cross-sectional study including 6,405 Northern European men and women aged 30-60 years from the general population of Copenhagen, Denmark. Data were collected with self-administered questionnaires, a physical examination, a 2 hour oral glucose tolerance test, and various blood tests. J shaped associations were observed between alcohol and diabetes, metabolic syndrome (MS), systolic and diastolic blood pressure, triglyceride, total cholesterol, and total homocysteine. Positive associations were observed with insulin sensitivity and HDL cholesterol, and a negative association with insulin release. Only a few of the selected ADH and ALDH gene variants was observed to have an effect. The ADH1c (rs1693482) fast metabolizing CC genotype was associated with an increased risk of impaired glucose tolerance (IGT)/diabetes compared to the CT and TT genotypes. Significant interactions were observed between alcohol and ADH1b (rs1229984) with respect to LDL and between alcohol and ALDH2 (rs886205) with respect to IGT/diabetes.

CONCLUSIONS/SIGNIFICANCE

The selected ADH and ALDH gene variants had only minor effects, and did not seem to markedly modify the health effects of alcohol drinking. The observed statistical significant associations would not be significant, if corrected for multiple testing.

Combined analyses of 20 common obesity susceptibility variants

OBJECTIVE

Genome-wide association studies and linkage studies have identified 20 validated genetic variants associated with obesity and/or related phenotypes. The variants are common, and they individually exhibit small-to-modest effect sizes.

RESEARCH DESIGN AND METHODS

In this study we investigate the combined effect of these variants and their ability to discriminate between normal weight and overweight/obese individuals. We applied receiver operating characteristics (ROC) curves, and estimated the area under the ROC curve (AUC) as a measure of the discriminatory ability. The analyses were performed cross-sectionally in the population-based Inter99 cohort where 1,725 normal weight, 1,519 overweight, and 681 obese individuals were successfully genotyped for all 20 variants.

RESULTS

When combining all variants, the 10% of the study participants who carried more than 22 risk-alleles showed a significant increase in probability of being both overweight with an odds ratio of 2.00 (1.47-2.72), P = 4.0 x 10(-5), and obese with an OR of 2.62 (1.76-3.92), P = 6.4 x 10(-7), compared with the 10% of the study participants who carried less than 14 risk-alleles. Discrimination ability for overweight and obesity, using the 20 single nucleotide polymorphisms (SNPs), was determined to AUCs of 0.53 and 0.58, respectively. When combining SNP data with conventional nongenetic risk factors of obesity, the discrimination ability increased to 0.64 for overweight and 0.69 for obesity. The latter is significantly higher (P < 0.001) than for the nongenetic factors alone (AUC = 0.67).

CONCLUSIONS

The discriminative value of the 20 validated common obesity variants is at present time sparse and too weak for clinical utility, however, they add to increase the discrimination ability of conventional nongenetic risk factors.

Moderate physical activity is associated with lower ApoB/ApoA-I ratios independently of other risk factors in healthy, middle-aged men

Low-density lipoprotein is recognized as a primary vascular risk factor. However, recent data favor apolipoprotein (apo)B and apoA-I as risk factors with higher predictive values than conventional lipids. We investigated how leisure-time physical activity relates to the serum apoB/apoA-I ratio in middle-aged men. The results showed that compared with a sedentary lifestyle, moderate physical activity was associated with a decreased apoB/apoA-I ratio (1.01 ± 0.28 vs 0.87 ± 0.24, P < .05) and increased apoA-I levels (1.30 ± 0.20 g/L vs 1.43 ± 0.22 g/L, P < .05), whereas vigorous activity was required to observe a reduction in apoB levels (1.27 ± 0.28 g/L vs 1.14 ± 0.24 g/L, P < .05). A covariate analysis showed that leisure time physical activity was also associated with reduced apoB/apoA-I ratios after adjustment for smoking, systolic blood pressure and waist circumference. Importantly, this association was seen at moderate levels of physical activity, supporting the notion that some activity is better than none.

Metabolic risk profiles and associated risk factors among Vietnamese adults in Ho Chi Minh City

BACKGROUND

A clustering of metabolic risk factors increases the likelihood of cardiovascular diseases. This study reports the metabolic risk profiles and the prevalence of metabolic risk factors and associated factors among Vietnamese adults in Ho Chi Minh City.

METHODS

A cross-sectional study was carried out in a representative sample of adults aged 25-64 years in Ho Chi Minh City in 2005. Metabolic risk factors, including central obesity, elevated fasting glucose, elevated total cholesterol, and raised blood pressure, were collected to estimate their prevalence and association with socioeconomic and health-related behavioral risk factors. Multivariate logistic models were performed to examine the associations between socioeconomic and behavioral risk factors and the odds of having metabolic risk factors.

RESULTS

The prevalence of individual risk components was: 28.9% high blood pressure, 18.3% central obesity, 16.8% high total cholesterol, and 6.4% high fasting glucose. There were significant gender differences in central obesity and high blood pressure. The prevalence of metabolic risk cluster (two or more risk factors) was 17.0% in men and 17.6% in women. The metabolic risk cluster appeared earlier in men, but women showed higher rates at older ages. Increasing age and household wealth were associated with the metabolic risk cluster across both genders, but additional risk factors in men were smoking in the past and in women education level and sitting and reclining time.

CONCLUSIONS

Strategies to prevent metabolic risk factors through the prevention of abdominal obesity must be established for young adults and should include promoting physical activity, healthy eating, and preventing alcohol abuse and tobacco use.

Differential relationship between physical activity and progression to diabetes by glucose tolerance status: the Inter99 Study

AIMS/HYPOTHESIS

The aim of the study was to analyse how strongly commuting and leisure-time physical activity affect progression to diabetes and to study whether this relationship is different in individuals with isolated impaired fasting glucose (i-IFG) and isolated impaired glucose tolerance (i-IGT).

METHODS

We studied the incidence of diabetes in 4,031 individuals without diabetes at baseline who participated in the baseline and 5 year follow-up examinations of a population-based primary prevention study, the Inter99 Study. Glucose tolerance status at baseline and at follow-up were based on OGTTs. Commuting and leisure-time physical activity at baseline were assessed by questionnaire. We present rate ratios from Poisson regression analyses adjusted for relevant confounders.

RESULTS

The progression rate to diabetes was lower among physically active individuals in the total study population and particularly among those with i-IGT. The associations were attenuated and lost statistical significance after further adjustment for BMI. We observed no impact of physical activity on the progression to diabetes in individuals with i-IFG.

CONCLUSIONS/INTERPRETATION

Physical activity was associated with a lower progression to diabetes in the total study population and in individuals with i-IGT, a condition primarily characterised by muscle insulin resistance. Physical activity did not predict progression to diabetes in individuals with i-IFG, a condition primarily characterised by hepatic insulin resistance. Our results suggest that there is a differential relationship between physical activity and progression to diabetes among those with i-IFG and i-IGT. Therefore, clinical trials testing the effect of physical activity on progression from i-IFG to diabetes are needed.

TRIAL REGISTRATION

ClinicalTrials.gov ID No.: NCT00289237

FUNDING

The Danish Medical Research Council, the Danish Center for Evaluation and Health Technology Assessment, Novo Nordisk, Copenhagen County, the Danish Heart Foundation, the Danish Diabetes Association, the Danish Pharmaceutical Association, the Augustinus Foundation, the Ib Henriksen Foundation and the Becket Foundation.

Lifestyle and genetic determinants of folate and vitamin B12 levels in a general adult population

Danish legislation regarding food fortification has been very restrictive resulting in few fortified food items on the Danish market. Folate and vitamin B12 deficiency is thought to be common due to inadequate intakes but little is known about the actual prevalence of low serum folate and vitamin B12 in the general population. The aim of the present study was to evaluate the folate and vitamin B12 status of Danish adults and to investigate associations between vitamin status and distinct lifestyle and genetic factors. The study included a random sample of 6784 individuals aged 30–60 years. Information on lifestyle factors was obtained by questionnaires and blood samples were analysed for serum folate and vitamin B12 concentrations and several genetic polymorphisms. The overall prevalence of low serum folate ( < 6·8 nmol/l) was 31·4 %. Low serum folate was more common among men than women and the prevalence was lower with increasing age. Low serum folate was associated with smoking, low alcohol intake, high coffee intake, unhealthy diet, and the TT genotype of the methylenetetrahydrofolate reductase (MTHFR)-C677T polymorphism. The overall prevalence of low serum vitamin B12 ( < 148 pmol/l) was 4·7 %. Low serum vitamin B12 was significantly associated with female sex, high coffee intake, low folate status, and the TT genotype of the MTHFR-C677T polymorphism. In conclusion, low serum folate was present in almost a third of the adult population in the present study and was associated with several lifestyle factors whereas low serum concentrations of vitamin B12 were less common and only found to be associated with a few lifestyle factors.

The relationship between lifestyle and self-reported health in a general population: the Inter99 study

OBJECTIVES

The aim of this paper is to describe the relationship between smoking status, dietary habits, physical activity and alcohol intake, and mental and physical self-reported health in a general population.

MEASURES

A large population-based study Inter99, Copenhagen, Denmark, 1999-2006. Self-reported health-related quality of life was measured by Short Form 12 (SF-12). Mental and physical health component scores were computed.

RESULTS

At baseline, SF-12 was completed by 6305 (92.3%) participants in the intervention groups, and 3017 (72.4%) persons in the control group. In cross-sectional analyses, persons with an unhealthy lifestyle reported significantly worse physical and mental health than persons with a healthier lifestyle. In longitudinal data, using adjusted multivariate analyses (N=3,084), we found an association between increased physical activity at five-year follow-up and improvement in physical health ( odds ratio=2.30 (95% confidence interval=1.7-3.2)) in the high-intensity intervention group. Improvement in mental health was associated with a much healthier diet at 5-year follow-up than at baseline ( odds ratio=1.68 (95% confidence interval=1.1-2.5)).

CONCLUSIONS

This study describes the negative relationship between unhealthy lifestyle and self-reported mental and physical health in a general population. Also, it shows the impact of improvements in lifestyle on self-reported health in a general population, which has not been investigated before.

A walk (or cycle) to the park: active transit to neighborhood amenities, the CARDIA study

BACKGROUND

Building on known associations between active commuting and reduced cardiovascular disease (CVD) risk, this study examines active transit to neighborhood amenities and differences between walking and cycling for transportation.

METHODS

Year-20 data from the Coronary Artery Risk Development in Young Adults study (3549 black and white adults aged 38-50 years in 2005-2006) were analyzed in 2008-2009. Sociodemographic correlates of transportation mode (car-only, walk-only, any cycling, other) to neighborhood amenities were examined in multivariable multinomial logistic models. Gender-stratified multivariable linear or multinomial regression models compared CVD risk factors across transit modes.

RESULTS

Active transit was most common to parks and public transit stops; walking was more common than cycling. Among those who used each amenity, active transit (walk-only and any cycling versus car-only transit) was more common in men and those with no live-in partner and less than full-time employment (significant ORs [95% CI] ranging from 1.56 [1.08, 2.27] to 4.54 [1.70, 12.14]), and less common in those with children. Active transit to any neighborhood amenity was associated with more favorable BMI, waist circumference, and fitness (largest coefficient [95% CI] -1.68 [-2.81, -0.55] for BMI, -3.41 [-5.71, -1.11] for waist circumference [cm], and 36.65 [17.99, 55.31] for treadmill test duration [seconds]). Only cycling was associated with lower lifetime CVD risk classification.

CONCLUSIONS

Active transit to neighborhood amenities was related to sociodemographics and CVD risk factors. Variation in health-related benefits by active transit mode, if validated in prospective studies, may have implications for transportation planning and research.

Active commuting and cardiovascular disease risk: the CARDIA study

BACKGROUND

There is little research on the association of lifestyle exercise, such as active commuting (walking or biking to work), with obesity, fitness, and cardiovascular disease (CVD) risk factors.

METHODS

This cross-sectional study included 2364 participants enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study who worked outside the home during year 20 of the study (2005-2006). Associations between walking or biking to work (self-reported time, distance, and mode of commuting) with body weight (measured height and weight); obesity (body mass index [BMI], calculated as weight in kilograms divided by height in meters squared, >or= 30); fitness (symptom-limited exercise stress testing); objective moderate-vigorous physical activity (accelerometry); CVD risk factors (blood pressure [oscillometric systolic and diastolic]); and serum measures (fasting measures of lipid, glucose, and insulin levels) were separately assessed by sex-stratified multivariable linear (or logistic) regression modeling.

RESULTS

A total of 16.7% of participants used any means of active commuting to work. Controlling for age, race, income, education, smoking, examination center, and physical activity index excluding walking, men with any active commuting (vs none) had reduced likelihood of obesity (odds ratio [OR], 0.50; 95% confidence interval [CI], 0.33-0.76), reduced CVD risk: ratio of geometric mean triglyceride levels (trig(active))/(trig(nonactive)) = 0.88 (95% CI, 0.80 to 0.98); ratio of geometric mean fasting insulin (FI(active))/(FI(nonactive)) = 0.86 (95% CI, 0.78 to 0.93); difference in mean diastolic blood pressure (millimeters of mercury) (DBP(active)) - (DBP(nonactive)) = -1.67 (95% CI, -3.20 to -0.15); and higher fitness: mean difference in treadmill test duration (in seconds) in men (TT(active)) - (TT(nonactive)) = 50.0 (95% CI, 31.45 to 68.59) and women (TT(active)) - (TT(nonactive)) = 28.77 (95% CI, 11.61 to 45.92).

CONCLUSIONS

Active commuting was positively associated with fitness in men and women and inversely associated with BMI, obesity, triglyceride levels, blood pressure, and insulin level in men. Active commuting should be investigated as a modality for maintaining or improving health.

Predictors of future fasting and 2-h post-OGTT plasma glucose levels in middle-aged men and women-the Inter99 study

AIMS

Screening and prevention strategies for Type 2 diabetes require insight into the aetiological and potentially different risk factors leading to early impairments of fasting plasma glucose (FPG) and 2-h post-load plasma glucose (2hPG) levels. We studied whether risk factors predicting subtle elevations of FPG levels were different from those predicting elevations of 2hPG levels in men and women.

METHODS

We used baseline and 5-year follow-up data from middle-aged men and women with normal glucose tolerance (NGT) at baseline in the Danish population-based Inter99 study (n = 3164). Anthropometric and non-anthropometric baseline predictors of the 5-year FPG and 2hPG levels were estimated in linear regression models stratified by gender.

RESULTS

In men, but not in women, smoking and family history of diabetes predicted increased FPG levels, whereas high physical activity predicted a decline in 2hPG levels. Among the anthropometric variables, large waist circumference was the strongest predictor of increased FPG levels in men, whereas high body mass index (BMI) was the strongest predictor of increased FPG levels in women. In both men and women, BMI and waist circumference were equally strong in predicting 2hPG levels. Furthermore, short height predicted increased 2hPG levels in men, and short height and low hip circumference predicted increased 2hPG levels in women.

CONCLUSIONS

Risk factors that predict future FPG levels are different from those predicting future 2hPG levels. Furthermore, different risk factors predict glycaemic levels in men compared with women. These findings indicate that different aetiological pathways may lead to Type 2 diabetes in men and women.

Five-year change in physical activity is associated with changes in cardiovascular disease risk factors: the Inter99 study

OBJECTIVE

To evaluate whether five-year changes in self-reported physical activity level were associated with changes in waist circumference, weight, serum lipids and blood pressure.

METHODS

In the Inter99 study (1999-2006) in Copenhagen, Denmark, 4039 men and women (30-60 years) answered questions on lifestyle and provided blood samples and anthropometric measures at baseline and after five years. Multiple regression analyses were performed with five-year value of each cardiovascular biomarker as outcome and change in physical activity level as explanatory variable.

RESULTS

Approximately 50% of the study population were men (n=2023). Change in physical activity level was inversely associated with change in weight (p<0.0001), waist (p<0.0001), diastolic blood pressure (p=0.04), total cholesterol (p=0.006), LDL (p=0.007), triglycerides (p=0.02) and with a composite risk score "the Copenhagen risk score" (p<0.0001), and positively associated with HDL in men (p=0.01).

CONCLUSION

Five-year changes in physical activity level were significantly associated with relevant changes in weight, waist circumference, diastolic BP and serum lipids in a population-based cohort of adult men and women. Change in physical activity level induced a significant change in HDL concentration in men only. Women's use of hormone replacement therapy may partly explain this gender difference.

Dietary patterns predict changes in two-hour post-oral glucose tolerance test plasma glucose concentrations in middle-aged adults

We examined whether the adherence to major dietary patterns at baseline of 5824 nondiabetic Danes (30-60 y) enrolled in the nonpharmacological Inter99 intervention predicted changes in fasting plasma glucose (FPG) and postchallenge 2-h plasma glucose (2h-PG) concentrations during a 5 y period and whether a potential association was dependent on baseline glucose tolerance status. Through principal component analysis, a score for a traditional dietary pattern (characterized by higher intakes of high-fat sandwich spreads, red meat, potatoes, butter and lard, low-fat fish, sandwich meat, and sauces) and a score for a modern dietary pattern (characterized by higher intakes of vegetables, fruit, vegetable oil/vinegar dressing, poultry, pasta, rice, and cereals) were estimated for each person at baseline. Random effect models adjusting for relevant confounders were used to estimate changes in repetitive measures of FPG and 2h-PG. A higher modern score (of 1 SD) predicted an annual decrease in 2h-PG of 0.015 mmol/L (P < 0.01) regardless of glucose tolerance status. For individuals with isolated impaired glucose tolerance, a higher traditional score (of 1 SD) predicted an annual increase in 2h-PG of 0.083 mmol/L (P < 0.0001). In conclusion, glucose tolerance status did not, in general, affect the predictive effect of the dietary patterns. The study suggests that the risk of worsening 2h-PG concentrations may be smaller for individuals with a high modern dietary pattern score characterized by high intakes of vegetables, fruit, vegetable oil/vinegar dressing, poultry, pasta, rice, and cereals.

Natural history of insulin sensitivity and insulin secretion in the progression from normal glucose tolerance to impaired fasting glycemia and impaired glucose tolerance: the Inter99 study

OBJECTIVE

The aim of this study was to describe the natural history of insulin secretion and insulin sensitivity in the development of isolated impaired fasting glycemia (i-IFG), isolated impaired glucose tolerance (i-IGT), and combined IFG/IGT.

RESEARCH DESIGN AND METHODS

Baseline and 5-year follow-up data from the Inter99 study were used. Individuals with normal glucose tolerance (NGT) at baseline and i-IFG, i-IGT, combined IFG/IGT, or NGT at the 5-year follow-up were examined with an oral glucose tolerance test (n = 3,145). Insulin sensitivity index (ISI), homeostasis model assessment of insulin sensitivity (HOMA-IS), early-phase insulin release (EPIR), and insulin secretion relative to insulin action (disposition index) were estimated.

RESULTS

Five years before the pre-diabetes diagnoses (i-IFG, i-IGT, and IFG/IGT), ISI, HOMA-IS, EPIR, and disposition index were lower than in individuals who maintained NGT. During the 5-year follow-up, individuals developing i-IFG experienced a significant decline only in HOMA-IS, whereas individuals developing i-IGT experienced significant declines in ISI, EPIR, and disposition index. Individuals with IFG/IGT exhibited pronounced declines in ISI, HOMA-IS, EPIR, and disposition index during the 5-year follow-up.

CONCLUSIONS

A stationary reduced insulin secretion followed by a decline in primarily hepatic insulin sensitivity characterizes the transition from NGT to i-IFG. In contrast, low whole-body insulin sensitivity with a secondary lack of beta-cell compensation is associated with the development of i-IGT. Thereby, i-IFG and i-IGT appear to result from different underlying mechanisms, which may have implications for the prevention and treatment of the diabetes that succeeds them.