Family history of diabetes identifies a group at increased risk for the metabolic consequences of obesity and physical inactivity in EPIC-Norfolk: a population-based study. The European Prospective Investigation into Cancer

Low occupational physical activity is associated with incident type 2 diabetes in overweight and obese individuals: a population-based cohort study

BACKGROUND

Leisure-time physical activity decreases the risk of type 2 diabetes. Whether occupational physical activity affects the risk of type 2 diabetes is still not fully understood. The primary aim of this study was to investigate the association between occupational physical activity and 10-year diabetes incidence in a general adult population in Northern Sweden. The secondary aim was to explore the moderating role of BMI on this association.

METHODS

This population-based, longitudinal cohort study included 16,282 diabetes-free individuals aged 28-52 years who participated in a cardiovascular intervention programme in Northern Sweden, and who reported the same occupational physical activity level at baseline and at 10-year follow-up. Incident type 2 diabetes was diagnosed based on oral glucose tolerance testing or a register-based diagnosis. Occupational physical activity was self-reported and categorized as: a) Low: 'Sedentary or standing' or 'Light but partly physically active', b) Moderate: 'Light and physically active', or c) High: Sometimes physically strenuous or 'Physically strenuous most of the time'. Odds ratios (OR) and 95% confidence intervals (CI) for incident diabetes were calculated using multivariable logistic regression analysis, adjusting for age, sex, smoking, education level, family history of diabetes, country of birth, intake of fruits and vegetables, leisure-time physical activity, prediabetes and BMI. Potential interactions between BMI category and T2D were tested using interaction terms in the multivariable model.

RESULTS

Six hundred twenty-four individuals developed type 2 diabetes in the 10 years between the first visit and the follow-up. A significant moderation effect of BMI on occupational physical activity was found (p = 0.01). Having a low level of occupational physical activity, compared with a moderate level of occupational physical activity, was associated with an increased risk of incident type 2 diabetes in overweight and obese individuals (OR 1.46, 95% CI 1.09-1.96), but not in those with normal weight (OR 0.80, 95% CI 0.52-1.23). High level of occupational physical activity was not associated with type 2 diabetes (OR 1.12, 95% CI 0.82-1.54).

CONCLUSIONS

Low occupational physical activity was associated with incident type 2 diabetes in overweight and obese individuals. Public-health efforts may benefit from encouraging less sitting and standing and more light physical activity during the workday.

Cross-sectional and Longitudinal Associations Between Family History of Type 2 Diabetes Mellitus, Hypertension, and Dyslipidemia and Their Prevalence and Incidence: Toranomon Hospital Health Management Center Study (TOPICS24)

OBJECTIVE

To examine the association between a positive family history (parents, siblings, and grandparents) of type 2 diabetes mellitus (T2DM), hypertension, and dyslipidemia and their prevalence and incidence in the same population.

PATIENTS AND METHODS

Data on 41,361 participants who underwent health examinations between January 1, 1997, and December 31, 2007, were analyzed, and the results of logistic and Cox regression analyses in the same cohort were examined.

RESULTS

Cross-sectional analyses showed that the prevalence of all three diseases increased with a positive family history, especially T2DM, with an odds ratio (OR) of 12.00 (95% CI, 7.82 to 18.41) when the number of affected relatives was greater than or equal to 3 with an OR of 20.43 (95% CI, 11.0 to 37.8) for a positive family history across three generations compared with no family history. However, redefining family history from "parents, siblings, and grandparents" to "parents and siblings" or "parents only" did not significantly change ORs for each disease. Among those with a positive family history and body mass index greater than or equal to 30.0 kg/m2 hypertension was 19 times more prevalent compared with no family history and body mass index of 18.5 to 24.9 kg/m2. In the longitudinal study, family history strongly influenced incident T2DM (hazard ratio[HR], 2.40; 95% CI, 1.93 to 2.98), hypertension (HR, 1.43; 95% CI, 1.26 to 1.62), and dyslipidemia (HR, 1.41; 95% CI, 1.08 to 1.83), respectively.

CONCLUSION

Obtaining a family history of these diseases was useful in identifying high-risk groups. Also, for T2DM, the influence of a positive family history was strongest with a marked increase in risk with overlap of affected family members, suggesting that a family history is useful for early detection and prevention.

Sitting time at work and cardiovascular disease risk-a longitudinal analysis of the Study on Mental Health at Work (S-MGA)

PURPOSE

This study analyzed longitudinal data to examine whether occupational sitting time is associated with increases in body mass index (BMI) and five-year cardiovascular disease (CVD) risk.

METHODS

We included 2,000 employed men and women (aged 31-60) from the German Study on Mental Health at Work (S-MGA) for a BMI analysis and 1,635 participants free of CVD at baseline (2011/2012) for a CVD analysis. Occupational sitting time was categorized into five groups (< 5, 5 to < 15, 15 to < 25, 25 to < 35, and ≥ 35 h per week). BMI change was measured from baseline (2011/2012) to follow-up (2017). Incident CVD included hypertension, heart disease, myocardial infarction, and stroke (all self-reported). Multiple linear regression examined the association between sitting time and BMI change, while modified Poisson regression analyzed CVD incidence, adjusting for age, sex, occupation, shift work, leisure activity, and smoking by sex. Covariates were self-reported.

RESULTS

Over five years, the average BMI change was 0.49 (SD 1.9). We found no association between baseline occupational sitting time and BMI changes, with consistent results in sensitivity analyses. During this period, 245 participants developed cardiovascular disease. There was no increased risk of CVD among those with more sitting time compared to less. No differences in risk were found between women and men.

CONCLUSION

There was no association between occupational sitting time and five-year changes in BMI or incident CVD.

Effectiveness of a culturally tailored diabetes education curriculum with real-time continuous glucose monitoring in a Latinx population with type 2 diabetes: the CUT-DM with CGM for Latinx randomised controlled trial study protocol

INTRODUCTION

The prevalence of type 2 diabetes (T2D) is increasing in the Latinx community. Despite telehealth and technology becoming more available, these resources are not reaching the Latinx population. Diabetes education is a cornerstone of treatment; however, access to culturally tailored content is a barrier to the Latinx population. Real-time continuous glucose monitoring (RT-CGM) is a patient-empowering tool that can improve glycaemic control, but it is not readily available for Latinx patients with T2D. We aim to evaluate a culturally tailored diabetes self-management education and support (DSMES) curriculum, using a team-based approach to improve glycaemic control, promote healthy behaviours and enhance patient access with the use of telehealth in Latinx individuals. The primary aim of the study is to evaluate the additive effectiveness of RT-CGM on glycaemia and behavioural changes among Latinx patients undergoing a culturally tailored DSMES. A sub aim of the study is to evaluate family members' change in behaviours.

METHODS

We propose a randomised controlled trial of blinded versus RT-CGM with 100 Latinx participants with T2D who will receive DSMES via telemedicine over 12 weeks (n=50 per group). The study will be conducted at a single large federally qualified health centre system. The control group will receive culturally tailored DSMES and blinded CGM. The intervention group will receive DSMES and RT-CGM. The DSMES is conducted by community health educators weekly over 12 weeks in Spanish or English, based on participant's language preference. Patients in the RT-CGM group will have cyclical use with a goal of 50 days wear time. The primary outcomes are changes in haemoglobin A1c and CGM-derived metrics at 3 and 6 months. The secondary outcomes include participants' self-management knowledge and behaviour and household members' change in lifestyle.

ETHICS AND DISSEMINATION

The study proposal was approved by the University of Washington ethics/institutional review board (IRB) Committee as minimal risk (IRB ID: STUDY00014396) and the Sea Mar IRB committee.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier: NCT05394844.

Investigating the relationship between lifestyle factors, family history, and diabetes mellitus in non-diabetic visitors to primary care centers

We investigated the risk levels associated with diabetes mellitus. They were assessed based on whether anyone in their family had a history of diabetes. The data collected are measurements of blood pressure, weight, height, and smoking habits, as well as physical activity and educational status. Based on the American Diabetes Association's (ADA) recommendations, the questionnaire included a diabetes risk assessment. The risk of diabetes was 76.3% among participants with a family history of diabetes. There is a 41.1% chance of diabetes among those participants whose fathers had diabetes, and a 39.3% chance of diabetes among those participants whose mothers had diabetes. Additionally, those participants who have siblings with diabetes were 24% at high risk for developing diabetes. The prevalence of the risk of having a family history of diabetes is higher in the women in the family (RR = 3.12; P = 0.0001) as compared to the men in the family (RR = 1.9; P = 0.0001). Risk of diabetes more in the male (1.13 times higher) in the current study based on the ADA scale. There is evidence that various factors, including lifestyle choices, physical attributes, and family history, influence the risk of developing diabetes in the current study. The results of the current study indicate that there is a strong association between patients with T2D and those who have a family history of diabetes. Considering Saudi Arabia's high diabetes risk, evidence-based lifestyle modifications are needed.

Patients with liver cirrhosis due to nonalcoholic steatohepatitis have lesser chances for liver transplantation

BACKGROUND

The main causes of liver cirrhosis have changed over the past decade. In Japan, the number of deceased donors is increasing but is still insufficient relative to the number of patients awaiting a liver transplant. This study aimed to assess the outcomes of candidates for liver transplantation.

METHODS

This was a retrospective study of adult patients who visited our department for consultation regarding liver transplantation from January 2009 to December 2020. Of a total of 601 patients, 336 were followed-up. The following data were collected and analyzed: patient's characteristics, liver etiology, Child-Pugh and MELD scores, and the eventual outcome, that is, whether liver transplantation was performed.

RESULTS

Only 153 of 336 (45.5%) patients underwent liver transplantation, of which 42 (27.5%) received deceased donor liver transplantation, and 129 (38.4%) died without transplantation. The proportion of patients who underwent liver transplantation was low among patients with nonalcoholic steatohepatitis (NASH) (10.7%) (P<0.001). The rate of qualified living donors was the lowest for patients with NASH (28.6%) and that for the other etiologies ranged from 55.6% to 67.4% (P=0.050).

CONCLUSION

Patients with liver cirrhosis due to NASH may have a lesser chance of undergoing liver transplantation from both living and deceased donors.

Associations of sleep duration with physical fitness performance and self-perception of health: a cross-sectional study of Taiwanese adults aged 23-45

Background

The relationship between sleep duration and physical fitness is one aspect of sleep health. Potential factors associated with sleep duration interfere with physical fitness performance, but the impact trends on physical fitness indicators remain unclear.

Methods

This study examined associations between sleep duration and physical fitness among young to middle-aged adults in Taiwan. A total of 42,781 Taiwanese adults aged 23–45 participated in the National Physical Fitness Examination Survey 2013 (NPFES-2013) in Taiwan between October 2013 and March 2014. A standardized structural questionnaire was used to record participants’ sleep duration, which was stratified as short (< 6 h/day (h/d)), moderate (6–7 h/d; 7–8 h/d; 8-9 h), and long (≥ 9 h/d) sleep duration groups. Physical fitness was assessed based on four components: body composition (body mass index [BMI], waist-to-height ratio [WHtR], and waist-to-hip ratio [WHR]), muscle strength and endurance (1-min bent-leg sit-up test [BS]), flexibility (sit-and-reach test [SR]), and cardiorespiratory endurance index (3-min step test [CEI]).

Results

By using analysis of covariance (ANCOVA), after sex grouping and age adjustment, we observed that sleep duration was significantly associated with obesity, functional fitness, and self-perception of health. The sleep duration for low obesity-related values (BMI, WHtR, and WHR) for men was 7–9 h/d, and that for women was 7–8 h/d. Sleeping more than 8 h/d showed poor functional fitness performances (BS and SR). For both sexes, sleep duration of 8–9 h/d was the optimal sleep duration for self-perceptions of health.

Conclusions

Our research found that there were wide and different associations of sleep duration with physical fitness and self-perception of health among Taiwanese adults aged 23–45, and there were differences in these associated manifestations between men and women. This study could be of great importance in regional public health management in Taiwan, and provide inspirations for clinical research on physical fitness.

Association of risk factors with type 2 diabetes: A systematic review

Diabetes is the leading cause of severe health complications and one of the top 10 causes of death worldwide. To date, diabetes has no cure, and therefore, it is necessary to take precautionary measures to avoid its occurrence. The main aim of this systematic review is to identify the majority of the risk factors for the incidence/prevalence of type 2 diabetes mellitus on one hand, and to give a critical analysis of the cohort/cross-sectional studies which examine the impact of the association of risk factors on diabetes. Consequently, we provide insights on risk factors whose interactions are major players in developing diabetes. We conclude with recommendations to allied health professionals, individuals and government institutions to support better diagnosis and prognosis of the disease.

Impact of sleep-disordered breathing on glucose metabolism among individuals with a family history of diabetes: the Nagahama study

STUDY OBJECTIVES

It is well known that a family history of diabetes (FHD) is a definitive risk factor for type 2 diabetes. It has not been known whether sleep-disordered breathing (SDB) increases the prevalence of diabetes in those with an FHD.

METHODS

We assessed SDB severity in 7,477 study participants by oximetry corrected by objective sleep duration determined by wrist actigraphy. Glycated hemoglobin ≥6.5% and/or current medication for diabetes indicated the presence of diabetes. In addition to the overall prevalence, the prevalence of recent-onset diabetes during the nearly 5 years before the SDB measurements were made was investigated.

RESULTS

Of the 7,477 participants (mean age: 57.9; range: 34.2-80.7; SD: 12.1 years; 67.7% females), 1,569 had an FHD. The prevalence of diabetes in FHD participants with moderate-to-severe SDB (MS-SDB) was higher than in those without SDB (MS-SDB vs without SDB: all, 29.3% vs 3.3% [P < .001]; females, 32.6% vs 1.9% [P < .001]; males, 26.2% vs 11.7% [P = .037]). However, multivariate analysis showed that MS-SDB was significantly associated with a higher prevalence of diabetes only in FHD-positive females (odds ratio [95% confidence interval]: females, 7.43 [3.16-17.45]; males, 0.92 [0.37-2.31]). Among the FHD-positive participants, the prevalence of recent-onset diabetes was higher in those with MS-SDB than those without SDB, but only in females (MS-SDB vs without SDB: 21.4% vs 1.1%; P < 0.001).

CONCLUSIONS

MS-SDB was associated with diabetes risk in females with an FHD, and future studies are needed on whether treatment of SDB in females with an FHD would prevent the onset of diabetes.

Association and Interaction Analysis of Lipid Accumulation Product with Impaired Fasting Glucose Risk: A Cross-Sectional Survey

AIMS

Lipid accumulation product (LAP) is put forward as a powerful marker showing the accumulation of visceral fat. The present study is aimed at (i) analyzing the predictive performances of LAP in the identification of impaired fasting glucose (IFG) in Chinese population and (ii) exploring the potentially interactive effect between LAP and other factors on IFG risk.

METHODS

Analysis was conducted on the data obtained from a community-based cross-sectional survey in Chinese population, and all the participants enrolled were required to complete a face-to-face questionnaire survey and related health checks. Then, for the purpose of comparing predictive values between LAP and conventional obesity indices for IFG, relevant analysis was carried out on the receiver operating characteristic (ROC) curve. The assessment of interactive effects was conducted by employing the three indicators as follows: (1) RERI (the relative excess risk due to interaction), (2) AP (attributable proportion due to interaction), and (3) SI (synergy index).

RESULTS

A total of 1777 participants (748 males and 1029 females) were involved in the final analysis. It was finally obtained that the prevalence rate of IFG was 14.1% in total, 15.5% for males and 13.1% for females, respectively. In logistic regression analysis, individuals with LAP levels in the fourth quartile had a significant higher risk of getting IFG in comparison with that of the lowest quartile (crude OR: 4.58, 95% CI: 3.01-6.98; adjusted OR: 3.81, 95% CI: 2.33-6.23). In addition, it was indicated by the ROC curve analysis that LAP showed a better performance in discriminating IFG risk than BMI in both males (Z = 2.20, P = 0.028) and females (Z = 2.13, P = 0.033). However, LAP displayed a higher predictability in comparison with WC only in females (Z = 2.07, P = 0.038), but not in males (Z = 0.18, P = 0.860). Furthermore, LAP and family history of diabetes were able to impose significant synergistic interaction on the risk of IFG, which was indicated by all the parameters in females (RERI: 2.52, 95% CI: 0.19-4.84; AP: 0.47, 95% CI: 0.20-0.74; SI: 2.39, 95% CI: 1.17-4.87) and males (RERI: 2.18, 95% CI: 0.08-4.73; AP: 0.43, 95% CI: 0.07-0.79; SI: 2.15, 95% CI: 1.03-5.45). However, none of the indicators showed significant interaction between LAP and smoking on the risk of IFG in females (RERI: 0.92, 95% CI: -2.79-4.63; AP: 0.20, 95% CI: -0.50-0.92; SI: 1.37, 95% CI: 0.42-4.52). Meanwhile, there was also no significant interaction between LAP and smoking on the risk of IFG in males as indicated by the value of SI (2.22, 95% CI: 0.80-6.21).

CONCLUSION

It was concluded that LAP was significantly related to a higher risk of IFG in Chinese population, and its performance was superior to that of conventional obesity indices, especially in females. Apart from that, LAP with family history of diabetes may have an interactive effect that can impose a great influence on the development of IFG.

High risk of conversion to diabetes in first-degree relatives of individuals with young-onset type 2 diabetes: a 12-year follow-up analysis

AIM

Family history of diabetes is an established risk factor for Type 2 diabetes, but the impact of a family history of young-onset diabetes (onset < 40 years) on future risk of diabetes among first-degree relatives is unclear. In this prospective study, we examined the influence of family history of late- versus young-onset diabetes on the development of diabetes in a young to middle-aged Chinese population.

METHODS

Some 365 siblings identified through probands with Type 2 diabetes and 452 participants from a community-based health awareness project (aged 18-55 years) who underwent metabolic assessment during the period 1998-2002 were followed to 2012-2013 to determine their glycaemic status. Multivariate logistic regression was performed to investigate the association of family history of diabetes presented at different age categories with development of diabetes.

RESULTS

In this cohort, 53.4% (n = 167) of participants with a family history of young-onset diabetes, 30.1% (n = 68) of those with a family history of late-onset diabetes and 14.4% (n = 40) of those without a family history developed diabetes. Using logistic regression, family history of diabetes presented at ages ≥ 50, 40-49, 30-39 and < 30 years, increased conversion to diabetes with respective odds ratios of 2.4, 5.8, 9.4 and 7.0 (P < 0.001 for all), after adjustment for socio-economic status, smoking, obesity, hypertension and dyslipidaemia. Among participants without diabetes at baseline, risk association of family history of late-onset diabetes with incident diabetes was not sustained, whereas that of family history of young-onset diabetes remained robust on further adjustment for baseline glycaemic measurements.

CONCLUSIONS

First-degree relatives of people with Type 2 diabetes, especially relatives of those with young-onset diabetes, are at high risk for diabetes.

Excess Medical Care Costs Associated with Physical Inactivity among Korean Adults: Retrospective Cohort Study

Physical inactivity is a major risk factor for chronic diseases and premature death. The increased health risks associated with physical inactivity may also generate a heavier economic burden to society. We estimated the direct medical costs attributable to physical inactivity among adultsusing data from the 2002–2010 Korean National Health Insurance Service-National Sample Cohort. A total of 68,556 adults whose reported physical activity status did not change during the study period was included for this study. Propensity scores for inactive adults were used to match 23,645 inactive groups with 23,645 active groups who had similar propensity scores. We compared medical expenditures between the two groups using generalized linear models with a gamma distribution and a log link. Direct medical costs were based on the reimbursement records of all medical facilities from 2005 to 2010. The average total medical costs for inactive individuals were $1110.5, which was estimated to be 11.7% higher than the costs for physically active individuals. With respect to specific diseases, the medical costs of inactive people were significantly higher than those of active people, accounting for approximately 8.7% to 25.3% of the excess burden. Physical inactivity is associated with considerable medical care expenditures per capita among Korean adults.

Maternal dietary patterns and gestational diabetes mellitus: a large prospective cohort study in China

Few studies have explored the relationship between dietary patterns and the risk of gestational diabetes mellitus (GDM). Evidence from non-Western areas is particularly lacking. In the present study, we aimed to examine the associations between dietary patterns and the risk of GDM in a Chinese population. A total of 3063 pregnant Chinese women from an ongoing prospective cohort study were included. Data on dietary intake were collected using a FFQ at 24-27 weeks of gestation. GDM was diagnosed using a 75 g, 2 h oral glucose tolerance test. Dietary patterns were determined by principal components factor analysis. A log-binomial regression model was used to examine the associations between dietary pattern and the risk of GDM. The analysis identified four dietary patterns: vegetable pattern; protein-rich pattern; prudent pattern; sweets and seafood pattern. Multivariate analysis showed that the highest tertile of the vegetable pattern was associated with a decreased risk of GDM (relative risk (RR) 0·79, 95% CI 0·64, 0·97), compared with the lowest tertile, whereas the highest tertile of the sweets and seafood pattern was associated with an increased risk of GDM (RR 1·23, 95% CI 1·02, 1·49). No significant association was found for either the protein-rich or the prudent pattern. The protective effect of a high vegetable pattern score was more evident among women who had a family history of diabetes (P for interaction=0·022). These findings suggest that the vegetable pattern was associated with a decreased risk of GDM, while the sweets and seafood pattern was associated with an increased risk of GDM. These findings may be useful in dietary counselling during pregnancy.

Physical activity, sedentary time and gain in overall and central body fat: 7-year follow-up of the ProActive trial cohort

OBJECTIVE

The objective of this study is to examine the independent associations of time spent in moderate-to-vigorous physical activity (MVPA) and sedentary (SED-time), with total and abdominal body fat (BF), and the bidirectionality of these associations in adults at high risk of type 2 diabetes.

DESIGN AND SUBJECTS

We measured MVPA (min per day) and SED-time (h per day) by accelerometry, and indices of total (body weight, fat mass (FM), BF% and FM index) and abdominal BF (waist circumference (WC)) using standard procedures in 231 adults (41.3 ± 6.4 years) with parental history of type 2 diabetes (ProActive UK) at baseline, 1-year and 7-year follow-up. Mixed effects models were used to quantify the independent associations (expressed as standardised β-coefficients (95% confidence interval (CI))) of MVPA and SED-time with fat indices, using data from all three time points. All models were adjusted for age, sex, intervention arm, monitor wear time, follow-up time, smoking status, socioeconomic status and MVPA/SED-time.

RESULTS

MVPA was inversely and independently associated with all indices of total BF (for example, 1 s.d. higher MVPA was associated with a reduction in FM, β = -0.09 (95% CI: -0.14, -0.04) s.d.) and abdominal BF (for example, WC: β = -0.07 (-0.12, -0.02)). Similarly, higher fat indices were independently associated with a reduction in MVPA (for example, WC: β = -0.25 (-0.36, -0.15); FM: β = -0.27 (-0.36, -0.18)). SED-time was positively and independently associated with most fat indices (for example, WC: β = 0.03 (-0.04, 0.09); FM: β = 0.10 (0.03, 0.17)). Higher values of all fat indices independently predicted longer SED-time (for example, WC: β = 0.10 (0.02, 0.18), FM: β = 0.15 (0.07, 0.22)).

CONCLUSIONS

The associations of MVPA and SED-time with total and abdominal BF are bidirectional and independent among individuals at high risk for type 2 diabetes. The association between BF and MVPA is stronger than the reciprocal association, highlighting the importance of considering BF as a determinant of decreasing activity and a potential consequence. Promoting more MVPA and less SED-time may reduce total and abdominal BF.

Interactions between sleep, circadian function, and glucose metabolism: implications for risk and severity of diabetes

Sleep disturbances, including sleep insufficiency and sleep fragmentation, have been linked to abnormal glucose metabolism and increased diabetes risk. Well-controlled laboratory studies have provided insights regarding the underlying mechanisms. Several large prospective studies suggest that these sleep disturbances are associated with an increased risk of incident diabetes. Obstructive sleep apnea, which combines sleep fragmentation and hypoxemia, is a major risk factor for insulin resistance and possibly diabetes. Whether glycemic control in type 2 diabetes patients can be improved by treating sleep apnea remains controversial. Recently, sleep disturbances during pregnancy and their relationship to gestational diabetes and hyperglycemia have received considerable attention owing to potential adverse effects on maternal and fetal health. Additionally, evidence from animal models has identified disruption of the circadian system as a putative risk factor for adverse metabolic outcomes. The purpose of this review is to provide an update on the current state of knowledge linking sleep disturbances, circadian dysfunction, and glucose metabolism. Experimental, prospective, and interventional studies are discussed.

Physical inactivity, insulin resistance, and the oxidative-inflammatory loop

Epidemiological data indicate that physical inactivity, a main factor of global energetic imbalance, is involved in the worldwide epidemic of obesity and metabolic disorders such as insulin resistance. Although the complex pathogenesis of insulin resistance is not fully understood, literature data accumulated during the past decades clearly indicate that the activation of the oxidative-inflammatory loop plays a major role. By activating the oxidative-inflammatory loop in insulin-sensitive tissues, fat gain and adipose tissue dysfunction likely contribute to induce insulin resistance during chronic and prolonged physical inactivity. However, in the past years, evidence has emerged showing that early insulin resistance also occurs after very short-term exposure to physical inactivity (1-7 days) without any fat gain or energetic imbalance. The possible role of liver disturbances or endothelial dysfunction is suggested, but further studies are necessary to really conclude. Inactive skeletal muscle probably constitutes the primary triggering tissue for the development of early insulin resistance. In the present review, we discuss on the current knowledge about the effect of physical inactivity on whole-body and peripheral insulin sensitivity, and how local inflammation and oxidative stress arising with physical inactivity could potentially induce insulin resistance. We assume that early muscle insulin resistance allows the excess nutrients to shift in the storage tissues to withstand starvation through energy storage. We also consider when chronic and prolonged, physical inactivity over an extended period of time is an underestimated contributor to pathological insulin resistance and hence indirectly to numerous chronic diseases.

Effects of sleep restriction on the human plasma metabolome

This study examined the effects of recurrent sleep restriction on the plasma metabolome of adults with familial risk of type 2 diabetes. Eleven healthy adults (6M/5F; mean [SD] age: 26 [3]years; BMI 23.5 [2.3]kg/m(2)) with parental history of type 2 diabetes participated in a two-condition, two-period randomized crossover study at the Clinical Resource Center at an academic hospital. Each participant completed two 8-night inpatient sessions with restricted (5.5-h time-in-bed) vs. adequate (8.5-h time-in-bed) sleep opportunity while daily food intake and physical activity were carefully controlled. A combination of two UHPLC/MS/MS platforms and one GC/MS platform was used to measure 362 biochemicals in fasting plasma samples collected from study participants the morning after each 8-night sleep treatment. Relative concentrations of 12 amino acids and related metabolites were increased when sleep was curtailed. Sleep restriction also induced elevations in several fatty acid, bile acid, steroid hormone, and tricarboxylic acid cycle intermediates. In contrast, circulating levels of glucose, some monosaccharides, gluconate, and five-carbon sugar alcohols tended to decline when sleep was reduced. Recurrent sleep curtailment affected multiple pathways of intermediary metabolism in adults at risk for type 2 diabetes. An elevation in plasma amino acids and related biochemicals was the most pronounced metabolic signature seen in response to 8 nights of sleep restriction.

Joint effect of family history of diabetes with obesity on prevalence of type 2 diabetes mellitus among Chinese and Finnish men and women

OBJECTIVE

To study joint effect of family history of diabetes (FHD) with obesity on prevalence of type 2 diabetes mellitus in the Chinese and in the Finns.

METHODS

A total of 1091 Chinese men and 1706 women, 1472 Finnish men and 1694 women, 45-74 years of age were studied. The probability and odds ratio (OR) of having diabetes were estimated using logistic regression analysis. The synergy index (SI) and relative excess risk due to interaction (RERI) of FHD with body mass index (BMI) or waist circumference (WC) was calculated.

RESULTS

Age-standardized prevalence of diabetes was higher in individuals with FHD than in those without in both the Chinese and Finns. Compared with individuals without FHD and with BMI <30 kg/m(2), ORs (95% confidence intervals [CI]) for diabetes were 2.7 (1.8, 4.0), 2.8 (1.9, 4.0), 9.1 (5.9, 13.9), respectively, in Finnish men with BMI ≥30 kg/m(2) alone, with FHD alone and with both (SI [95% CI] = 2.4 [1.4, 3.9], RERI = 4.6 [1.3, 8.0]); the corresponding figures were 1.7 (1.0, 2.9), 2.7 (1.8, 4.2) and 4.4 (1.9, 10.4) in Chinese men (SI = 1.4 [0.4, 4.9] RERI = 1.0 [-2.9, 5.0]). They were 3.5 (2.1, 5.8), 2.1 (1.3, 3.4) and 6.8 (4.1, 11.2) in Finnish women (SI = 1.6 [0.9, 2.8], RERI = 2.2 [-0.4, 4.9]), and 1.6 (1.1, 2.2), 2.1 (1.5, 3.0), 3.5 (1.9, 6.4) in Chinese women (SI = 1.5 [0.6, 3.8], RERI = 0.8 [-1.4, 3.0]). The pattern of synergistic effect of FHD with WC on diabetes was similar to that seen with BMI in the Finns but no effect was seen in the Chinese.

CONCLUSIONS

Both obesity and FHD are independent risk factors for diabetes, but their joint effect is significant only in Finnish men.

The link between family history and risk of type 2 diabetes is not explained by anthropometric, lifestyle or genetic risk factors: the EPIC-InterAct study

AIMS/HYPOTHESIS

Although a family history of type 2 diabetes is a strong risk factor for the disease, the factors mediating this excess risk are poorly understood. In the InterAct case-cohort study, we investigated the association between a family history of diabetes among different family members and the incidence of type 2 diabetes, as well as the extent to which genetic, anthropometric and lifestyle risk factors mediated this association.

METHODS

A total of 13,869 individuals (including 6,168 incident cases of type 2 diabetes) had family history data available, and 6,887 individuals had complete data on all mediators. Country-specific Prentice-weighted Cox models were fitted within country, and HRs were combined using random effects meta-analysis. Lifestyle and anthropometric measurements were performed at baseline, and a genetic risk score comprising 35 polymorphisms associated with type 2 diabetes was created.

RESULTS

A family history of type 2 diabetes was associated with a higher incidence of the condition (HR 2.72, 95% CI 2.48, 2.99). Adjustment for established risk factors including BMI and waist circumference only modestly attenuated this association (HR 2.44, 95% CI 2.03, 2.95); the genetic score alone explained only 2% of the family history-associated risk of type 2 diabetes. The greatest risk of type 2 diabetes was observed in those with a biparental history of type 2 diabetes (HR 5.14, 95% CI 3.74, 7.07) and those whose parents had been diagnosed with diabetes at a younger age (<50 years; HR 4.69, 95% CI 3.35, 6.58), an effect largely confined to a maternal family history.

CONCLUSIONS/INTERPRETATION

Prominent lifestyle, anthropometric and genetic risk factors explained only a marginal proportion of the excess risk associated with family history, highlighting the fact that family history remains a strong, independent and easily assessed risk factor for type 2 diabetes. Discovering factors that will explain the association of family history with type 2 diabetes risk will provide important insight into the aetiology of type 2 diabetes.

Family History of Diabetes, Acculturation, and the Metabolic Syndrome among Mexican Americans: Proyecto SALSA

BACKGROUND

The purpose of this study was to examine effect modifiers of the relationship between family history of diabetes, a proxy for genetic predisposition, and the metabolic syndrome.

METHODS

Subjects were a cross-sectional sample of 205 Mexican-Americans patients of the San Ysidro Health Center in San Diego County. Self-reported parental history of diabetes was examined as a risk factor for individual metabolic syndrome traits (hyperglycemia, hypertension, abdominal obesity, hypertriglyceridemia and low HDL-cholesterol) and a composite phenotype, defined both by standard modified National Cholesterol Education Program- Adult Treatment Panel III (NCEP-ATPIII) criteria and using principal components analysis, in age and sex-adjusted multiple logistic and linear regression models.

RESULTS

Family history of diabetes was most strongly associated with individual traits of hyperglycemia (P = .0002) and low HDL-C (P = .001) and conferred a significant increased odds of metabolic syndrome defined by both NCEP-ATPIII criteria (odds ratio 3.57, 95% confidence interval 1.82, 7.01; P = .0002) and by principal components analysis (P = 0.003). Moreover, the family history association with metabolic syndrome was modified by number of years living in the United States (interaction P = .04). This same effect was not seen for diabetes (P = .19).

CONCLUSIONS

The results of our study support a common etiology for at least some components of the metabolic syndrome, especially hyperglycemia and low HDL-cholesterol, the basis of which may be genetic. Moreover, the effect of genes on these traits may be modified by longer duration in the United States, supporting the concept of gene-environment interaction in the development of the metabolic syndrome.

Type 2 diabetes in Asians: prevalence, risk factors, and effectiveness of behavioral intervention at individual and population levels

This review summarizes the current data on diabetes risk factors, prevalence, and prevention efforts in Asia and Asian migrant populations. Studies indicate that type 2 diabetes mellitus is a large and growing threat to public health in Asian populations. Furthermore, Asian subgroups (e.g., South Asians/Asian Indians, Chinese) have unique risk factor profiles for developing diabetes, which differ from other populations and between Asian ethnic groups. Lifestyle intervention programs are effective in preventing diabetes in Asians, as with other ethnicities. The strength of these findings is lessened by the lack of systematically collected data using objective measurements. Large epidemiologic studies of diabetes prevalence and risk factor profiles and translational trials identifying sustainable and culturally acceptable lifestyle programs for Asian subgroups are needed.

Sleep restriction decreases the physical activity of adults at risk for type 2 diabetes

STUDY OBJECTIVE

To test the hypothesis that recurrent sleep curtailment will result in decreased physical activity in adults at risk for type 2 diabetes.

DESIGN

Two-condition 2-period randomized crossover study.

SETTING

University General Clinical Research Center.

PARTICIPANTS

Eighteen healthy patients with parental history of type 2 diabetes (9 females and 9 males, age 27 yr [standard deviation 3], body mass index 23.7 [2.3] kg/m²).

INTERVENTIONS

Two week-long inpatient sessions with 8.5 or 5.5-hr nighttime sleep opportunity. Participants who exercised regularly (39%) could follow their usual exercise routines during both sessions.

MEASUREMENTS AND RESULTS

Sleep and total body movement were measured by wrist actigraphy and waist accelerometry. Subjective mood and vigor was assessed using visual analog scales. The main outcome was the comparison of total activity counts between sleep conditions. Ancillary endpoints included changes in sedentary, light, and moderate plus vigorous activity, and their association with changes in mood and vigor. Daily sleep was reduced by 2.3 hr (P < 0.001) and total activity counts were 31% lower (P = 0.020) during the 5.5-hr time-in-bed condition. This was accompanied by a 24% reduction in moderate-plus-vigorous activity time (P = 0.005) and more sedentary behavior (+21 min/day; P = 0.020). The decrease in daily activity during the 5.5-hr time-in-bed condition was seen mostly in participants who exercised regularly (-39 versus -4% in exercisers versus nonexercisers; P = 0.027). Sleep loss-related declines in physical activity correlated strongly with declines in subjective vigor (R = 0.90; P < 0.001).

CONCLUSIONS

Experimental sleep restriction results in decreased amount and intensity of physical activity in adults at risk for type 2 diabetes.

Validity of the occupational sitting and physical activity questionnaire

PURPOSE

Sitting at work is an emerging occupational health risk. Few instruments designed for use in population-based research measure occupational sitting and standing as distinct behaviors. This study aimed to develop and validate brief measure of occupational sitting and physical activity.

METHODS

A convenience sample (n = 99, 61% female) was recruited from two medium-sized workplaces and by word-of-mouth in Sydney, Australia. Participants completed the newly developed Occupational Sitting and Physical Activity Questionnaire (OSPAQ) and a modified version of the MONICA Optional Study on Physical Activity Questionnaire (modified MOSPA-Q) twice, 1 wk apart. Participants also wore an ActiGraph accelerometer for the 7 d in between the test and retest. Analyses determined test-retest reliability with intraclass correlation coefficients and assessed criterion validity against accelerometers using the Spearman ρ.

RESULTS

The test-retest intraclass correlation coefficients for occupational sitting, standing, and walking for OSPAQ ranged from 0.73 to 0.90, while that for the modified MOSPA-Q ranged from 0.54 to 0.89. Comparison of sitting measures with accelerometers showed higher Spearman correlations for the OSPAQ (r = 0.65) than for the modified MOSPA-Q (r = 0.52). Criterion validity correlations for occupational standing and walking measures were comparable for both instruments with accelerometers (standing: r = 0.49; walking: r = 0.27-0.29).

CONCLUSIONS

The OSPAQ has excellent test-retest reliability and moderate validity for estimating time spent sitting and standing at work and is comparable to existing occupational physical activity measures for assessing time spent walking at work. The OSPAQ brief instrument measures sitting and standing at work as distinct behaviors and would be especially suitable in national health surveys, prospective cohort studies, and other studies that are limited by space constraints for questionnaire items.

Associations of cardiorespiratory fitness and parental history of diabetes with risk of type 2 diabetes

AIMS

We examined the independent and joint associations of cardiorespiratory fitness (CRF) and parental diabetes history on type 2 diabetes risk.

METHODS

A cohort of 11,627 individuals aged 20-79 years was free of baseline diabetes, cardiovascular disease, and cancer. We measured CRF using a maximal treadmill exercise test, and parental diabetes by a medical history questionnaire.

RESULTS

During an average 5.5 year follow-up, 572 cases of type 2 diabetes occurred. Compared with the least fit 20%, the multivariate hazard ratio (HR) (95% CI) was 0.59 (0.43-0.83) for the middle fit 40%, and 0.53 (0.38-0.75) for the high fit 40%. Those with parental diabetes had a 1.40-fold higher risk for developing type 2 diabetes. In combined analyses using fit, no parental diabetes as the referent, unfit with no parental diabetes was 1.79 (95% CI 1.25-2.57) times more likely to develop type 2 diabetes, while the risk with parental diabetes was 1.41 (95% CI 1.12-1.78) and 2.37 (95% CI 1.25-4.49) times higher in the fit and unfit, respectively.

CONCLUSIONS

While high CRF did not fully attenuate the risk of diabetes associated with parental diabetes, being fit reduces diabetes risk regardless of parental history.

Reduced physical activity in adults at risk for type 2 diabetes who curtail their sleep

Adults with parental history of type 2 diabetes have high metabolic morbidity, which is exacerbated by physical inactivity. Self-reported sleep <6 h/day is associated with increased incidence of obesity and diabetes, which may be mediated in part by sleep-loss-related reduction in physical activity. We examined the relationship between habitual sleep curtailment and physical activity in adults with parental history of type 2 diabetes. Forty-eight young urban adults with parental history of type 2 diabetes (27 F/21 M; mean (s.d.) age 26 (4) years; BMI 23.8 (2.5) kg/m(2)) each completed 13 (2) days of sleep and physical activity monitoring by wrist actigraphy and waist accelerometry while following their usual lifestyle at home. Laboratory polysomnography was used to screen for sleep disorders. The primary outcome of the study was the comparison of total daily activity counts between participants with habitual sleep <6 vs. ≥6 h/night. Secondary measures included daily time spent sedentary and in light, moderate, and vigorous physical activity. Short sleepers had no sleep abnormalities and showed signs of increased sleep pressure consistent with a behavioral pattern of habitual sleep curtailment. Compared to participants who slept ≥6 h/night, short sleepers had 27% fewer daily activity counts (P = 0.042), spent less time in moderate-plus-vigorous physical activity (-43 min/day; P = 0.010), and remained more sedentary (+69 min/day; P = 0.026). Our results indicate that young urban adults with parental history of type 2 diabetes who habitually curtail their sleep have less daily physical activity and more sedentary living, which may enhance their metabolic risk.

Sleep and eating behavior in adults at risk for type 2 diabetes

Insufficient quantity and quality of sleep may modulate eating behavior, everyday physical activity, overall energy balance, and individual risk of obesity and type 2 diabetes. We examined the association of habitual sleep quantity and quality with the self-reported pattern of eating behavior in 53 healthy urban adults with parental history of type 2 diabetes (30 F/23 M; mean (s.d.) age: 27 (4) years; BMI: 23.9 (2.3) kg/m(2)) while taking into consideration the amount of their everyday physical activity. Participants completed 13 (3) days of sleep and physical activity monitoring by wrist actigraphy and waist accelerometry while following their usual lifestyle at home. Overnight laboratory polysomnography was used to screen for sleep disorders. Subjective sleep quality was measured with the Pittsburgh Sleep Quality Index. Eating behavior was assessed using the original 51-item and the revised 18-item version of the Three-Factor Eating Questionnaire including measures of cognitive restraint, disinhibition, hunger, and uncontrolled and emotional eating. In multivariable regression analyses adjusted for age, BMI, gender, race/ethnicity, level of education, habitual sleep time measured by wrist actigraphy and physical activity measured by waist accelerometry, lower subjective sleep quality was associated with increased hunger, more disinhibited, uncontrolled and emotional eating, and higher cognitive restraint. There was no significant association between the amount of sleep measured by wrist actigraphy and any of these eating behavior factors. Our findings indicate that small decrements in self-reported sleep quality can be a sensitive indicator for the presence of potentially problematic eating patterns in healthy urban adults with familial risk for type 2 diabetes.

História familiar positiva de diabetes altera a resposta cronotrópica ao exercício agudo

O objetivo do presente estudo foi verificar os efeitos de uma sessão de exercício aeróbio (SEA) no perfil metabólico e hemodinâmico em filhos de diabéticos do tipo II. Jovens saudáveis do sexo masculino foram divididos em dois grupos: filhos de diabéticos (FD, n = 7) e filhos de normoglicêmicos (FN, n = 7). Foram realizadas medidas metabólicas (triglicérides e glicemia) e cardiovasculares (pressão arterial, PA, e frequência cardíaca, FC) em repouso, durante e após a SEA. A SEA foi realizada em esteira ergométrica com duração de 30 minutos e intensidade progressiva. Os grupos apresentaram valores semelhantes em relação ao triglicérides, PA e FC em repouso. A glicemia de jejum do grupo FD foi maior em relação ao grupo FN (99 ± 2 versus 89 ± 2mg/dL). O grupo FD apresentou maior resposta cronotrópica no início da SEA quando comparado ao grupo FN (86 ± 4 versus 125 ± 8bpm), mas a FC foi semelhante entre os grupos nas demais intensidades. No quinto minuto de recuperação da SEA a FC foi maior no grupo FD comparado ao grupo FN (FN: 88 ± 3 versus FD: 97 ± 4bpm). A PA foi semelhante entre os grupos durante e após a SEA. Os resultados demonstram que filhos de diabéticos jovens já apresentam alterações metabólicas em repouso e resposta exacerbada da FC no início e nos primeiros minutos de recuperação da SEA, sugerindo um maior risco cardiovascular nessa população.

Occupational sitting and health risks: a systematic review

CONTEXT

Emerging evidence suggests that sedentary behavior (i.e., time spent sitting) may be negatively associated with health. The aim of this study was to systematically review the evidence on associations between occupational sitting and health risks.

EVIDENCE ACQUISITION

Studies were identified in March-April 2009 by literature searches in PubMed, PsycINFO, CENTRAL, CINAHL, EMBASE, and PEDro, with subsequent related-article searches in PubMed and citation searches in Web of Science. Identified studies were categorized by health outcome. Two independent reviewers assessed methodologic quality using a 15-item quality rating list (score range 0-15 points, higher score indicating better quality). Data on study design, study population, measures of occupational sitting, health risks, analyses, and results were extracted.

EVIDENCE SYNTHESIS

43 papers met the inclusion criteria (21% cross-sectional, 14% case-control, 65% prospective); they examined the associations between occupational sitting and BMI (n=12); cancer (n=17); cardiovascular disease (CVD, n=8); diabetes mellitus (DM, n=4); and mortality (n=6). The median study-quality score was 12 points. Half the cross-sectional studies showed a positive association between occupational sitting and BMI, but prospective studies failed to confirm a causal relationship. There was some case-control evidence for a positive association between occupational sitting and cancer; however, this was generally not supported by prospective studies. The majority of prospective studies found that occupational sitting was associated with a higher risk of DM and mortality.

CONCLUSIONS

Limited evidence was found to support a positive relationship between occupational sitting and health risks. The heterogeneity of study designs, measures, and findings makes it difficult to draw definitive conclusions at this time.

Diabetes risk assessment in Mexicans and Mexican Americans: effects of parental history of diabetes are modified by adiposity level

OBJECTIVE

Parental diabetes history is a well-known risk factor for type 2 diabetes and considered strong evidence for a genetic basis of type 2 diabetes. Whether this relationship is affected by other known risk factors, specifically obesity, remains unclear, possibly due to a relative paucity of lean diabetic patients.

RESEARCH DESIGN AND METHODS

This issue was investigated using data from a high-risk population from Mexico (National Health Survey 2000, n = 27,349), with observations replicated using U.S. citizens of Mexican descent from the National Health and Nutrition Examination Survey 2001-2002 and 2003-2004 (n = 1,568).

RESULTS

As expected, positive parental diabetes was a significant risk factor for type 2 diabetes, regardless of age, sex, or adiposity level. However, positive parental diabetes conferred greater risk in leaner individuals than in their overweight peers (P = 0.001). In other words, the effect of BMI on type 2 diabetes risk was smaller in the presence of parental diabetes history.

CONCLUSIONS

These findings suggest that parental diabetes is a stronger risk factor for type 2 diabetes in the absence of obesity. Thus, studies in lean diabetic patients could help identify type 2 diabetes susceptibility genes. This study reinforces the concept that parental diabetes and BMI are independent type 2 diabetes risk factors and suggests that glycemic screening may be helpful in assessing type 2 diabetes risk in individuals with parental diabetes history, regardless of their overweight status.

Clinical Characteristics of Type 2 Diabetes Patients according to Family History of Diabetes

Background

Type 2 diabetes mellitus (T2DM) has a strong genetic component, and its prevalence is notably increased in the family members of T2DM patients. However, there are few studies about the family history of T2DM. We carried out this study to assess the influences of family history on clinical characteristics in T2DM patients.

Methods

This is a cross-sectional study involving 651 T2DM patients. Patient history and physical examination were performed and fasting blood was taken. If any first degree relative was diabetic, a family history of diabetes was considered to exist.

Results

Among the total 621 patients, 38.4% had a family history of diabetes. Patients with a family history had a younger age, higher weight, younger age at diagnosis and higher triglyceride level than did those without a family history. Dyslipidemia medication and metabolic syndrome were more prevalent in familial diabetes. Sex, blood pressure, previous treatment for diabetes, HbA1c, C-peptide, total cholesterol, high density lipoprotein cholesterol, and low density lipoprotein cholesterol were not different between familial and non-familial diabetes. Upon multiple linear regression analysis, the family history of diabetes remained significantly associated with serum triglyceride level.

Conclusion

In T2DM patients with a family history of diabetes, the disease tended to develop earlier. Metabolic syndrome and cardiovascular risk factors are more prevalent in familial T2DM than they were in non-familial T2DM. These results support the necessity of earlier screening for diabetes in family members of T2DM patients and more active prevention against cardiovascular disease in T2DM patients with a family history.

Reducing health risk in family members of patients with type 2 diabetes: views of first degree relatives

Background

Patients with type 2 diabetes can have an important role in discussing health risk within families. This study aimed to establish the acceptability to first degree relatives towards their relative with type 2 diabetes intervening as health promoters in their own families, using the Health Belief Model as a theoretical framework for evaluation.

Methods

Cross-sectional questionnaire design. Survey questionnaire for first degree relative (sibling or child) mailed to a random sample of patients with type 2 diabetes registered with an urban hospital diabetes clinic (n = 607 eligible patients). Patients were asked to pass on questionnaires to one to two first degree relatives.

Results

Questionnaires were returned from 257 families (42% response rate) with two responses provided by 107 families (a total of 364 questionnaires). The majority (94%) of first degree relatives of patients with type 2 diabetes would like to be informed about reducing their risk. Half (48%) of respondents reported being spoken to by a relative with type 2 diabetes about their risk of diabetes. Those spoken to were more likely to see themselves at risk of diabetes, to worry about developing diabetes and to view diabetes as a serious condition.

Conclusions

A role for patients with type 2 diabetes in discussing health risk in their family appears to be acceptable to many relatives. Discussion of risk and interventions to reduce health risk with their relatives should be encouraged in patients with type 2 diabetes.

Racial differences in the interaction between family history and risk factors associated with diabetes in the National Health and Nutritional Examination Survey, 1999-2004

PURPOSE

We sought to determine whether the association between family history, a surrogate for genetic predisposition, and diabetes was modified by any known diabetes risk factors and if these relationships were constant across different ethnic groups.

METHODS

We examined 10,899 adults from the National Health and Nutrition Examination Survey (1999 -2004) to identify interactions between family history and clinical, demographic, and lifestyle variables for the outcome of diabetes using logistic regression analysis in racial/ethnic subgroups.

RESULTS

There was significant heterogeneity by race/ethnicity in the interaction between covariates and family history in relation to diabetes. In black (P = 0.0001) and Hispanic (P = 0.013), but not white (P = 0.75) subgroups, high-familial risk was a strong risk factor for diabetes among lean individuals but less so among overweight or obese subjects.Among blacks, high-familial risk conferred a 20-fold increased odds of diabetes among lean subjects and only a sixfold increased odds among obese individuals.

CONCLUSIONS

These findings suggest possible race/ethnic-specific differences in gene by environment interaction and identify body mass index as an important effect modifier of familial risk in diabetes in non-white populations. These findings may help guide future genetic studies and improve the utility of family history as a public health screening tool.

Understanding of Diabetes Mellitus and Health-preventive Behaviour Among Singaporeans

Introduction: To study the understanding and perceived vulnerability of diabetes mellitus among Singapore residents, and determine the predictors associated with screening for diabetes mellitus among the people without the condition. Materials and Methods: A population-based survey was conducted from December 2004 to October 2005 involving Singapore residents aged 15 to 69 years. Using a standard questionnaire, Health Survey Officers interviewed household members on their understanding and perceived vulnerability of diabetes mellitus and associated cardiovascular risk factors. Data were analysed using SPSS v13. Results: The response rate was 84.5%. Of 2,632 respondents, 291 (11.1%) have diabetes mellitus. Compared to respondents without diabetes, respondents with the disease had better understanding of diabetes and they had favourable health practice of screening for cardiovascular risk factors. Having diabetes mellitus was not associated with a healthier lifestyle. Among non-diabetics, those who had a family history of diabetes had better knowledge and health practices than those who had not. They were significantly more likely to recognise the symptoms and signs (61.5% vs 54.5%) and the causes of diabetes (70% vs 58.2%); and were more likely to have ever tested for diabetes (76.1% vs 60.4%), with P <0.001. Socio-demographic characteristics, family history, understanding and perception on the vulnerability of diabetes were identified as predictors associated with health screening for the disease. Conclusion: Among all respondents, better understanding was found to be associated with favourable health-preventive behaviours. However, it did not translate into healthier lifestyle. Cultural and socio-demographic profiles must be factored in for any effort on lifestyle modifications. Key words: Diabetes, Health Screening, Understanding, Vulnerability

Impact of a physical activity intervention program on cognitive predictors of behaviour among adults at risk of Type 2 diabetes (ProActive randomised controlled trial)

BACKGROUND

In the ProActive Trial an intensive theory-based intervention program was no more effective than theory-based brief advice in increasing objectively measured physical activity among adults at risk of Type 2 diabetes. We aimed to illuminate these findings by assessing whether the intervention program changed cognitions about increasing activity, defined by the Theory of Planned Behaviour, in ways consistent with the theory.

METHODS

N = 365 sedentary participants aged 30-50 years with a parental history of Type 2 diabetes were randomised to brief advice alone or to brief advice plus the intervention program delivered face-to-face or by telephone. Questionnaires at baseline, 6 and 12 months assessed cognitions about becoming more physically active. Analysis of covariance was used to test intervention impact. Bootstrapping was used to test multiple mediation of intervention impact.

RESULTS

At 6 months, combined intervention groups (face-to-face and telephone) reported that they found increasing activity more enjoyable (affective attitude, d = .25), and they perceived more instrumental benefits (e.g., improving health) (d = .23) and more control (d = .32) over increasing activity than participants receiving brief advice alone. Stronger intentions (d = .50) in the intervention groups than the brief advice group at 6 months were partially explained by affective attitude and perceived control. At 12 months, intervention groups perceived more positive instrumental (d = .21) and affective benefits (d = .29) than brief advice participants. The intervention did not change perceived social pressure to increase activity.

CONCLUSION

Lack of effect of the intervention program on physical activity over and above brief advice was consistent with limited and mostly small short-term effects on cognitions. Targeting affective benefits (e.g., enjoyment, social interaction) and addressing barriers to physical activity may strengthen intentions, but stronger intentions did not result in more behaviour change. More powerful interventions which induce large changes in TPB cognitions may be needed. Other interventions deserving further evaluation include theory-based brief advice, intensive measurement of physical and psychological factors, and monitoring of physical activity. Future research should consider a wider range of mediators of physical activity change, assess participants' use of self-regulatory strategies taught in the intervention, and conduct experimental studies or statistical modelling prior to trial evaluation. ISRCTN61323766.

Parental history of type 2 diabetes mellitus, metabolic syndrome, and cardiometabolic risk factors in Asian Indian adolescents

The objective was to study the influence of parental history of type 2 diabetes mellitus on prevalence of the metabolic syndrome (MS) and other cardiometabolic risk factors in Asian Indian adolescents. Adolescents aged 12 to 19 years (N = 321) were recruited from the Chennai Urban Rural Epidemiology Study. Based on parental diabetic status, 3 groups were studied: group 1, offspring of parents with normal glucose tolerance (n = 105); group 2, offspring of 1 diabetic parent (n = 114); and group 3, offspring of 2 diabetic parents (n = 102). Subjects underwent blood pressure and anthropometric measurements as well as an oral glucose tolerance test and a fasting lipid profile. Metabolic syndrome was diagnosed using the International Diabetes Federation definition. Body mass index (P < .001) and waist and hip circumference (P < .05 for group 2 and P < .001 for group 3) were significantly higher in groups 2 and 3 compared with group 1. High-density lipoprotein cholesterol was significantly lower in groups 2 and 3 compared with group 1 (P < .05). Serum triglycerides were significantly higher in group 3 (P < .05) compared with the other 2 groups. Adolescents in group 3 (P < .001) and group 2 (P < .05) were significantly more overweight and had more abdominal obesity compared with those in group 1. Impaired fasting glucose and impaired glucose tolerance were also significantly higher in group 3 compared with the other 2 groups. High blood pressure showed an increasing trend from group 1 to group 3 (P for trend < .05). Two metabolic abnormalities were present in 7.6%, 14.9%, and 22.5% of adolescents in groups 1, 2, and 3, respectively (trend chi(2): 9.04, P = .003). Prevalence of MS was higher in groups 2 and 3 compared with group 1 but did not reach statistical significance because of small numbers. The cardiometabolic profile of the parents was similar to that of the adolescents. Parental history of type 2 diabetes mellitus increases risk of not only glucose intolerance but also other cardiometabolic risk factors like overweight, low high-density lipoprotein cholesterol, and high blood pressure in Asian Indian adolescents.

Will people with type 2 diabetes speak to family members about health risk?

OBJECTIVE

This study aimed to assess the potential for communication of familial risk by patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A questionnaire was completed by a random sample of patients with type 2 diabetes registered with a hospital diabetes clinic.

RESULTS

Two-thirds of patients (65%) had spoken to at least one sibling or child about diabetes risk. They were more likely to believe their family was at risk, to worry about their family developing diabetes, and to be aware of the seriousness of diabetes. The results revealed greater awareness of family risk of type 2 diabetes compared with those from previous studies.

CONCLUSIONS

Many patients with type 2 diabetes had already taken the initiative, without formal prompting, to talk to family members about their risk of diabetes. Discussion of risk and interventions to reduce risk should be encouraged within families.

Exercise training has greater effects on insulin sensitivity in daughters of patients with type 2 diabetes than in women with no family history of diabetes

AIMS/HYPOTHESIS

Sedentary offspring of patients with type 2 diabetes are often more insulin-resistant than persons with no family history of diabetes, but when active or fit offspring of type 2 diabetic patients are compared with non-diabetic persons, differences in insulin resistance are less evident. This study aimed to determine the effects of an exercise training intervention on insulin sensitivity in both groups.

METHODS

Women offspring (n = 34) of type 2 diabetic patients (offspring age 35.6 +/- 7.0 years, BMI 28.1 +/- 5.1 kg/m(2)) and 36 matched female controls (age 33.6 +/- 6.1 years, BMI 27.3 +/- 4.7 kg/m(2)) participated. Body composition, fitness and metabolic measurements were made at baseline and after a controlled 7 week exercise intervention.

RESULTS

At baseline, insulin sensitivity index (ISI) was 22% lower in offspring than controls (p < 0.05), despite similar body fat and maximal oxygen uptake (.VO(2max)) values in the two groups. ISI increased by 23% (p < 0.05) in offspring following the exercise intervention, compared with 7% (NS) in the controls. Increases in .VO(2max) were similar in both groups (controls 12%, offspring 15%, p < 0.05 for both). Plasma leptin concentrations decreased significantly in the offspring (-24%, p < 0.01) but not in controls (0%, NS). Change in ISI correlated significantly with baseline ISI (r = -0.47, p < 0.0005) and change in leptin (r = -0.43, p < 0.0005). The latter relationship was not attenuated by adjustment for changes in body fat.

CONCLUSIONS/INTERPRETATION

Offspring, but not controls, significantly increased ISI in response to an exercise intervention, indicating that insulin sensitivity is more highly modulated by physical activity in daughters of patients with type 2 diabetes than in women with no family history of the disease.

Elevated liver enzymes in women with a family history of diabetes

Both elevated liver enzymes and a family history of diabetes mellitus (FHDM) are independent risk factors for type 2 diabetes. This study evaluates the epidemiological association between elevated liver enzymes and FHDM. Subjects included 3512 women workers without diabetes, hepatitis, a smoking habit, or a history of alcohol intake. Blood samples and personal data were collected from all subjects. Subjects with FHDM had a higher mean body mass index (BMI: 23.9kg/m(2) vs. 23.4kg/m(2); p=0.003). Laboratory testing also revealed higher mean fasting plasma glucose (FPG: 5.67mmol/L vs. 5.22mmol/L; p<0.001), asparate aminotransferase (AST: 20.0IU/L vs. 19.2IU/L; p=0.049), alanine aminotransferase (ALT: 18.4IU/L vs. 16.7IU/L; p=0.004), gamma-glutamyltranspeptidase (GGT: 24.1IU/L vs. 20.5IU/L; p<0.001), and triglycerides (TG: 1.09mmol/L vs. 1.00mmol/L; p=0.011) for FHDM subjects, when adjusted for age and BMI. Multiple linear regression analysis revealed that FHDM, age, BMI, FPG, and TG were correlated with GGT (p=0.004 for FHDM; p<0.001 for age, BMI, FPG, and TG). Elevated liver enzymes were associated with FHDM. In particular, elevated GGT was related to FHDM, independent of the other variables. Elevated liver enzymes, probably due to fat deposition in the liver, may play a role in increasing the risk of diabetes in individuals with FHDM.

Efficacy of a theory-based behavioural intervention to increase physical activity in an at-risk group in primary care (ProActive UK): a randomised trial

BACKGROUND

Declining physical activity is associated with a rising burden of global disease. Efforts to reverse this trend have not been successful. We aimed to assess the efficacy of a facilitated behavioural intervention to increase the physical activity of sedentary individuals at familial risk of diabetes.

METHODS

We enrolled 365 sedentary adults who had a parental history of type 2 diabetes. They were recruited from either diabetes or family history registers at 20 general practice clinics in the UK. Eligible participants were randomly assigned to one of two intervention groups, or to a comparison group. All participants were posted a brief advice leaflet. One intervention group was offered a 1-year behaviour-change programme, to be delivered by trained facilitators in participants' homes, and the other the same programme by telephone. The programme was designed to alter behavioural determinants, as defined by the theory of planned behaviour, and to teach behaviour-change strategies. The principal outcome at 1 year was daytime physical activity, which was objectively measured as a ratio to resting energy expenditure. Analysis was by intention to treat. This study is registered as ISRCTN61323766.

FINDINGS

Of 365 patients, we analysed primary endpoints for 321 (88%) for whom we had data after 1 year of follow-up. At 1 year, the physical-activity ratio of participants who received the intervention, by either delivery route, did not differ from the ratio in those who were given a brief advice leaflet. The mean difference in daytime physical-activity ratio, adjusted for baseline, was -0.04 (95% CI -0.16 to 0.08). The physical-activity ratio did not differ between participants who were delivered the intervention face-to-face or by telephone (mean difference -0.05; 95% CI -0.19 to 0.10).

INTERPRETATION

A facilitated theory-based behavioural intervention was no more effective than an advice leaflet for promotion of physical activity in an at-risk group; therefore health-care providers should remain cautious about commissioning behavioural programmes into individual preventive health-care services.

Epidemiological studies of physical activity and diabetes risk, and implications for diabetes prevention

The evidence linking physical inactivity to the future risk of type 2 diabetes is strong, and modification of behaviour is a critical and effective element of strategies aimed at the prevention of this increasingly prevalent disorder. Two key unresolved epidemiologic issues relate to the type of activity that is likely to be maximally effective in preventing diabetes and the amount of activity that is required. Resolution of both these issues is likely to require a change in the way activity is measured, with a move away from self-report instruments, toward objective assessment of activity and the pattern and overall level of energy expenditure. It is also unclear whether the impact of physical activity on metabolic risk is homogenous across the population. Subgroups that might respond differently could be defined on the basis of characteristics such as age, degree of obesity, family history, ethnicity, and genetic risk, but the literature on effect modification is limited by study design issues. The identification of such subgroups could aid in the targeting of preventive interventions. An appropriate balance between individually tailored approaches aimed at those at high risk and interventions aimed at trying to shift physical activity levels in entire populations remains to be determined.

Family history of diabetes, awareness of risk factors, and health behaviors among African Americans

OBJECTIVES

We examined the role of family history of diabetes in awareness of diabetes risk factors and engaging in health behaviors.

METHODS

We conducted a cross-sectional analysis of 1122 African American adults without diabetes who were participants in Project DIRECT (Diabetes Interventions Reaching and Educating Communities Together).

RESULTS

After adjustment for age, gender, income, education, body mass index, and perceived health status, African Americans with a family history of diabetes were more aware than those without such a history of several diabetes risk factors: having a family member with the disease (relative risk [RR]=1.09; 95% confidence interval [CI]=1.03, 1.15), being overweight (RR=1.12; 95% CI=1.05, 1.18), not exercising (RR=1.17; 95% CI=1.07, 1.27), and consuming energy-dense foods (RR=1.10; 95% CI=1.00, 1.17). Also, they were more likely to consume 5 or more servings of fruits and vegetables per day (RR=1.31; 95% CI=1.02, 1.66) and to have been screened for diabetes (RR=1.21; 95% CI=1.12, 1.29).

CONCLUSIONS

African Americans with a family history of diabetes were more aware of diabetes risk factors and more likely to engage in certain health behaviors than were African Americans without a family history of the disease.

Population-based family case-control proband study on familial aggregation of metabolic syndrome: finding from Taiwanese people involved in Keelung community-based integrated screening (KCIS no. 5)

A population-based case-control proband study was undertaken to elucidate familial aggregation, independent environmental factors, and the interaction between them. A total of 7308 metabolic syndrome (MET-S) cases were identified from the Keelung community-based integrated screening programme between 1999 and 2002. The study has a case-control/family sampling design. A total of 1417 case probands were randomly selected from 3225 metabolic syndrome cases and the corresponding 2458 controls selected from 16,519 subjects without metabolic syndrome by matching on sex, age (+/-3 years) and place of residence. The generalized estimation equation model was used to estimate odds ratios and corresponding 95% confidence intervals. The risk for having metabolic syndrome among family members for cases versus control probands was 1.56-fold (1.29-1.89) after controlling for significant environmental factors. Higher risk of metabolic syndrome was found in parents than spouse. Low education against high education had 2.06-fold (1.36-3.13) risk for metabolic syndrome. Betel quid chewing was positively associated with the risk of MET-S, with 1.99-fold (1.13-3.53) risk for 1-9 pieces and 1.76-fold (0.96-3.23) risk for >or=10 pieces compared with non-chewer. Moderate and high intensity of non-occupational exercise led to 21.0% (OR=0.79 (0.63-0.98)) and 26.0% (OR=0.74 (0.59-0.94)) reduction in the risk for metabolic syndrome, respectively. The frequent consumption of vegetable reduced 24.0% (OR=0.76 (0.62-0.92)) risk for MET-S. The frequent consumption of coffee was associated the increased risk for metabolic syndrome (OR=1.32 (1.07-1.64)). The present study confirmed the risk of metabolic syndrome not only has the tendency towards familial aggregation but is affected by independent effect of environmental or individual correlates.

Combining information from common type 2 diabetes risk polymorphisms improves disease prediction

BACKGROUND

A limited number of studies have assessed the risk of common diseases when combining information from several predisposing polymorphisms. In most cases, individual polymorphisms only moderately increase risk (approximately 20%), and they are thought to be unhelpful in assessing individuals' risk clinically. The value of analyzing multiple alleles simultaneously is not well studied. This is often because, for any given disease, very few common risk alleles have been confirmed.

METHODS AND FINDINGS

Three common variants (Lys23 of KCNJ11, Pro12 of PPARG, and the T allele at rs7903146 of TCF7L2) have been shown to predispose to type 2 diabetes mellitus across many large studies. Risk allele frequencies ranged from 0.30 to 0.88 in controls. To assess the combined effect of multiple susceptibility alleles, we genotyped these variants in a large case-control study (3,668 controls versus 2,409 cases). Individual allele odds ratios (ORs) ranged from 1.14 (95% confidence interval [CI], 1.05 to 1.23) to 1.48 (95% CI, 1.36 to 1.60). We found no evidence of gene-gene interaction, and the risks of multiple alleles were consistent with a multiplicative model. Each additional risk allele increased the odds of type 2 diabetes by 1.28 (95% CI, 1.21 to 1.35) times. Participants with all six risk alleles had an OR of 5.71 (95% CI, 1.15 to 28.3) compared to those with no risk alleles. The 8.1% of participants that were double-homozygous for the risk alleles at TCF7L2 and Pro12Ala had an OR of 3.16 (95% CI, 2.22 to 4.50), compared to 4.3% with no TCF7L2 risk alleles and either no or one Glu23Lys or Pro12Ala risk alleles.

CONCLUSIONS

Combining information from several known common risk polymorphisms allows the identification of population subgroups with markedly differing risks of developing type 2 diabetes compared to those obtained using single polymorphisms. This approach may have a role in future preventative measures for common, polygenic diseases.

A causal modelling approach to the development of theory-based behaviour change programmes for trial evaluation

Theory-based intervention programmes to support health-related behaviour change aim to increase health impact and improve understanding of mechanisms of behaviour change. However, the science of intervention development remains at an early stage. We present a causal modelling approach to developing complex interventions for evaluation in randomized trials. In this approach a generic model links behavioural determinants, causally through behaviour, to physiological and biochemical variables, and health outcomes. It is tailored to context, target population, behaviours and health outcomes. The development of a specific causal model based on theory and evidence is illustrated by the ProActive programme, supporting increased physical activity among individuals at risk of Type 2 diabetes. The model provides a rational guide to appropriate measures, intervention points and intervention techniques, and can be tested quantitatively. Causal modelling is critically compared to other approaches to intervention development and evaluation, and research directions are indicated.

Epidemiological evidence for the role of physical activity in reducing risk of type 2 diabetes and cardiovascular disease

Epidemiological studies suggest that physically active individuals have a 30-50% lower risk of developing type 2 diabetes than do sedentary persons and that physical activity confers a similar risk reduction for coronary heart disease. Risk reductions are observed with as little as 30 min of moderate-intensity activity per day. Protective mechanisms of physical activity include the regulation of body weight; the reduction of insulin resistance, hypertension, atherogenic dyslipidemia, and inflammation; and the enhancement of insulin sensitivity, glycemic control, and fibrinolytic and endothelial function. Public health initiatives promoting moderate increases in physical activity may offer the best balance between efficacy and feasibility to improve metabolic and cardiovascular health in largely sedentary populations.

Genetic Factors in Type 2 Diabetes: The End of the Beginning?

The intensive search for genetic variants that predispose to type 2 diabetes was launched with optimism, but progress has been slower than was hoped. Even so, major advances have been made in the understanding of monogenic forms of the disease which together represent a substantial health burden, and a few common gene variants that influence susceptibility have now been unequivocally identified. Armed with a better understanding of the tools needed to detect such genes, it seems inevitable that the rate of progress will increase and the relevance of genetic information to the diagnosis, treatment, and prevention of diabetes will become increasingly tangible.

The ProActive trial protocol - a randomised controlled trial of the efficacy of a family-based, domiciliary intervention programme to increase physical activity among individuals at high risk of diabetes [ISRCTN61323766]

BACKGROUND

Increasing prevalence of obesity and disorders associated with sedentary living constitute a major global public health problem. While previous evaluations of interventions to increase physical activity have involved communities or individuals with established disease, less attention has been given to interventions for individuals at risk of disease.

METHODS/DESIGN

ProActive aims to evaluate the efficacy of a theoretical, evidence- and family-based intervention programme to increase physical activity in a sedentary population, defined as being at-risk through having a parental family history of diabetes. Primary care diabetes or family history registers were used to recruit 365 individuals aged 30-50 years, screened for activity level. Participants were assigned by central randomisation to three intervention programmes: brief written advice (comparison group), or a psychologically based behavioural change programme, delivered either by telephone (distance group) or face-to-face in the family home over one year. The protocol-driven intervention programme is delivered by trained facilitators, and aims to support increases in physical activity through the introduction and facilitation of a range of self-regulatory skills (e.g. goal setting). The primary outcome is daytime energy expenditure and its ratio to resting energy expenditure, measured at baseline and one year using individually calibrated heart rate monitoring. Secondary measures include self-report of individual and family activity, psychological mediators of behaviour change, physiological and biochemical correlates, acceptability, and costs, measured at baseline, six months and one year. The primary intention to treat analysis will compare groups at one-year post randomisation. Estimation of the impact on diabetes incidence will be modelled using data from a parallel ten-year cohort study using similar measures.

DISCUSSION

ProActive is the first efficacy trial of an intervention programme to promote physical activity in a defined high-risk group accessible through primary care. The intervention programme is based on psychological theory and evidence; it introduces and facilitates the use of self-regulatory skills to support behaviour change and maintenance. The trial addresses a range of methodological weaknesses in the field by careful specification and quality assurance of the intervention programme, precise characterisation of participants, year-long follow-up and objective measurement of physical activity. Due to report in 2005, ProActive will provide estimates of the extent to which this approach could assist at-risk groups who could benefit from changes in behaviours affecting health, and inform future pragmatic trials.