Components of metabolic syndrome predicting diabetes: no role of inflammation or dyslipidemia

Association of mean arterial pressure with 5-year risk of incident diabetes in Chinese adults：a secondary population-based cohort study

OBJECTIVE

Hypertension predicts the development of diabetes. However, there are still lacking high-quality studies on the correlation between mean arterial pressure (MAP) and incident diabetes. We aimed to explore the relationship between MAP and diabetes in Chinese adults.

DESIGN

This is a secondary retrospective cohort study and the data were downloaded from the 'DATADRYAD' database (www.Datadryad.org).

PARTICIPANTS

The study included 210 418 adults without diabetes at baseline between 2010 and 2016 across 32 sites and 11 cities in China.

SETTING

The target-independent and dependent variables were MAP measured at baseline and diabetes occurred during follow-up. Cox proportional hazards regression was used to explore the relationship between MAP and diabetes.

PRIMARY OUTCOME MEASURES

The outcome was incident diabetes, which was defined as fasting blood glucose ≥7.00 mmol/L and/or self-reported diabetes during follow-up. Patients were censored either at the time of the diagnosis or at the last visit, whichever comes first.

RESULTS

3927 participants developed diabetes during a 5-year follow-up. After adjusting covariates, MAP positively correlated with diabetes (HR=1.008, 95% CI 1.005 to 1.011, p<0.001), and the absolute risk difference was 0.02%. E-value analysis and multiple imputations were used to explore the robustness of the results. The relationship between MAP and diabetes was also non-linear, and the inflection point of MAP was 100.333 mm Hg. Subgroup analysis revealed a stronger association between MAP and diabetes in people with age (≥30,<50 years old), fasting plasma glucose <6.1 mmol/L and drinking. Additionally, receiver operating characteristic (ROC) curves showed the predictive performance of MAP for diabetes was similar to systolic blood pressure (SBP) (area under the curve (AUC)=0.694 with MAP vs AUC=0.698 with SBP).

CONCLUSIONS

MAP is an independent predictor for a 5-year risk of incident diabetes among Chinese adults. The relationship between MAP and diabetes is also non-linear. When MAP is below 100.333 mm Hg, MAP is closely positively related to diabetes.

Assessing Cognitive Factors of Modular Distance Learning of K-12 Students Amidst the COVID-19 Pandemic towards Academic Achievements and Satisfaction

The COVID-19 pandemic brought extraordinary challenges to K-12 students in using modular distance learning. According to Transactional Distance Theory (TDT), which is defined as understanding the effects of distance learning in the cognitive domain, the current study constructs a theoretical framework to measure student satisfaction and Bloom’s Taxonomy Theory (BTT) to measure students’ academic achievements. This study aims to evaluate and identify the possible cognitive capacity influencing K-12 students’ academic achievements and satisfaction with modular distance learning during this new phenomenon. A survey questionnaire was completed through an online form by 252 K-12 students from the different institutions of Occidental Mindoro. Using Structural Equation Modeling (SEM), the researcher analyses the relationship between the dependent and independent variables. The model used in this research illustrates cognitive factors associated with adopting modular distance learning based on students’ academic achievements and satisfaction. The study revealed that students’ background, experience, behavior, and instructor interaction positively affected their satisfaction. While the effects of the students’ performance, understanding, and perceived effectiveness were wholly aligned with their academic achievements. The findings of the model with solid support of the integrative association between TDT and BTT theories could guide decision-makers in institutions to implement, evaluate, and utilize modular distance learning in their education systems.

Plasma CD36 and Incident Diabetes: A Case-Cohort Study in Danish Men and Women

BACKGROUND

Membrane CD36 is a fatty acid transporter implicated in the pathogenesis of metabolic disease. We aimed to evaluate the association between plasma CD36 levels and diabetes risk and to examine if the association was independent of adiposity among Danish population.

METHODS

We conducted a case-cohort study nested within the Danish Diet, Cancer and Health study among participants free of cardiovascular disease, diabetes and cancer and with blood samples and anthropometric measurements (height, weight, waist circumference, and body fat percentage) at baseline (1993 to 1997). CD36 levels were measured in 647 incident diabetes cases that occurred before December 2011 and a total of 3,515 case-cohort participants (236 cases overlap).

RESULTS

Higher plasma CD36 levels were associated with higher diabetes risk after adjusting for age, sex and other lifestyle factors. The hazard ratio (HR) comparing high versus low tertile of plasma CD36 levels was 1.36 (95% confidence interval [CI], 1.00 to 1.86). However, the association lost its significance after further adjustment for different adiposity indices such as body mass index (HR, 1.23; 95% CI, 0.87 to 1.73), waist circumference (HR, 1.21; 95% CI, 0.88 to 1.68) or body fat percentage (HR, 1.20; 95% CI, 0.86 to 1.66). Moreover, raised plasma CD36 levels were moderately associated with diabetes risk among lean participants, but the association was not present among overweight/obese individuals.

CONCLUSION

Higher plasma CD36 levels were associated with higher diabetes risk, but the association was not independent of adiposity. In this Danish population, the association of CD36 with diabetes risk could be either mediated or confounded by adiposity.

Treadmill exercise alleviates diabetic cardiomyopathy by suppressing plasminogen activator inhibitor expression and enhancing eNOS in streptozotocin-induced male diabetic rats

OBJECTIVE

To investigate the biological mechanism of the effect of different intensity exercises on diabetic cardiomyopathy.

METHODS

87 raise specific pathogen SPF healthy 6-week-old male Sprague-Dawley rats, fed 6 weeks with high-fat diet for rats were used, and a diabetic model was established by intraperitoneal injection of streptozotocin - randomly selected 43 rats were divided into Diabetic control group (DCG, n = 10), Diabetic exercise group 1 (DEG1, n = 11), Diabetic exercise group 2 (DEG2, n = 11) and Diabetic exercise group 3 (DEG3, n = 11). The rats in DEG1 were forced to run on a motorized treadmill, the exercise load consisted of running at a speed of 10 m/min, the exercise load of the rats in DEG2 were running at a speed of 15 m/min, the exercise load of the rats in DEG3 were running at a speed of 20 m/min, for one hour once a day for 6 weeks. After 6 weeks of exercise intervention, glucose metabolism-related indexes in rats such as blood glucose (FBG), glycosylated serum protein (GSP) and insulin (FINS); cardiac fibrinolytic system parameters such as PAI-1 (plasminogen activator inhibitor 1), Von Willebrand factor (vWF), protein kinase C (PKC) and diacylglycerol (DAG); and serum level of NO, eNOS and T-NOS were measured.

RESULT

Compared with DCG, fasting blood glucose and GSP were decreased, while insulin sensitivity index and insulin level were increased in all rats of the three exercise groups. FBG decrease was statistically significant (P < 0.01), only GSP decrease was statistically significant (P < 0.05) in DEG1 and DEG2, PAI-1 in three exercise groups were significantly reduced (P < 0.05), plasma vWF levels in the three exercise groups were significantly lower than those in the DCG group (P < 0.01); PKC levels decreased dramatically in the three exercise groups and DAG levels decrease slightly (P < 0.05), but with no significant difference. Compared with DCG, the serum level of NO was significantly higher (P < 0.05), and eNOS level was significantly elevated (P < 0.05). T-NOS elevation was statistically significant in DEG1 (P < 0.05).

CONCLUSIONS

Low- and moderate-intensity exercise can better control blood glucose level in diabetic rats; myocardial PAI-1 in DEG1, DEG2 and DEG3 rats decreased significantly (P < 0.05), serum NO increased (P < 0.05) and eNOS increased (P < 0.05) significantly. Therefore, it is inferred that exercise improves the biological mechanism of diabetic cardiomyopathy by affecting the levels of PAI-1 and eNOS, and there is a dependence on intensity.

Time-cumulated blood pressure exposure and incident impairment of glucose tolerance and diabetes mellitus

BACKGROUND

With the marked increase in the prevalence of diabetes mellitus, it was the purpose of our study to assess a potential association of time-cumulated exposure to systolic (CumSBP) and of diastolic blood pressure (CumDBP) with onset of impaired glucose tolerance and diabetes mellitus.

METHODS

The prospective investigation included participants of the longitudinal Kailuan Study with three baseline examinations in 2006-2007, 2008-2009 and 2010-2011, re-examination in 2012-2013, and no diabetes mellitus at baseline. Cumulative blood pressure (BP) was calculated as cumBP = [(BP1 + BP2)/2 × time1-2] + [(BP2 + BP3)/2 × time2-3]. Based on cumSBP, the study population was stratified into four groups (cumSBP < 480mmHgxyear;n = 15,339; 480mmHgxyear ≤ cumSBP < 520mmHgxyear;n = 7214; 520mmHgxyears ≤ cumSBP < 560mmHgxyears;n = 5675; and cumSBP ≥ 560mmHgxyears;n = 10,576).

RESULTS

After adjusting for demographic, anthropomorphic, biochemical, socioeconomic and lifestyle parameters and as compared with the first group, the second, third and fourth group showed a significantly higher incidence of diabetes (P-trend < 0.001;hazard ratio (HR);95% confidence interval (CI):1.28(1.08,1.51),1.54(1.29,1.84), and 2.33(1.98,2.73), respectively), higher incidence of impairment of glucose tolerance (P-trend < 0.001;HR;95% CI1.17(1.02,1.33), 1.43(1.25,1.64), and 2.09(1.85,2.37), respectively), and higher incidence of diabetes developing out of an impairment of glucose tolerance (P-trend < 0.001;HR;95% CI:1.22(0.97,1.54),1.47(1.16,1.86), and 2.01(1.62,2.50), respectively). An increase in cumSBP by 10 mmHg/year or an increase in cumDBP by 5 mmHg/year was associated with a hazard ratio of incident diabetes of 1.04 (95% CI:1.03,1.04) and 1.02(1.02,1.03), respectively, with a hazard ratio of incident impairment of glucose tolerance of 1.04(95% CI:1.03,1.04) and 1.03(95% CI:1.02,1.03), respectively, and with a hazard ratio of incident diabetes developing from impairment of glucose tolerance of 1.04(95% CI:1.03,1.04) and 1.03(95% CI:1.02,1.03), respectively.

CONCLUSIONS

Time-cumulated exposure to elevated blood pressure was significantly associated with an elevated incidence of impaired glucose tolerance and diabetes.

Markers of fibrinolysis may predict development of lower extremity arterial disease in patients with diabetes: A longitudinal prospective cohort study with 10 years of follow-up

BACKGROUND

A previous cross-sectional study suggested that tissue plasminogen activator-activity might be an early marker of asymptomatic lower extremity arterial disease, but the long-term relationship is unknown.

SUBJECTS AND METHODS

This study included 96 diabetic (48 type 1/48 type 2) and 62 non-diabetic subjects aged 30-70 years without previously known lower extremity arterial disease (age: 50.3 ± 9.3 years, gender: M/W 47.5/52.5% and body mass index: 26.6 ± 4.5 kg/m(2)). The relationships between asymptomatic lower extremity arterial disease and fibrinolytic markers (tissue plasminogen activator-activity, tissue plasminogen activator-mass, plasminogen activator inhibitor-1 activity) at baseline and after 10 years were assessed by logistic regression analysis adjusting for age, hypertension, statin treatment, HbA1c, triglycerides and low-density lipoprotein cholesterol as fixed covariates.

RESULTS

The tissue plasminogen activator-activity at baseline and at the 10-year follow-up significantly predicted the presence of sign(s) of lower extremity arterial disease (odds ratio = 1.78, 95% confidence interval: 1.02-3.10, p = 0.043 and odds ratio = 1.78, 95% confidence interval: 1.12-2.23, p = 0.014, respectively). In addition, tissue plasminogen activator-mass at the 10-year follow-up was associated with signs of lower extremity arterial disease (odds ratio = 1.07, 95% confidence interval: 1.00-1.15, p = 0.046). Baseline age, hypertension and HbA1c were independently associated with sign(s) of lower extremity arterial disease at 10 years (odds ratio = 1.09, 95% confidence interval: 1.04-1.14, p = < 0.001; odds ratio = 3.68, 95% confidence interval: 1.67-8.12, p = 0.001 and odds ratio = 1.54, 95% confidence interval: 1.21-1.95, p = < 0.001, respectively).

CONCLUSION

This long-term study supports previous findings of a significant association between asymptomatic lower extremity arterial disease and tissue plasminogen activator-activity. Thus, tissue plasminogen activator-activity may be an early marker of lower extremity arterial disease although the mechanism of this relationship remains unclear.

Signs of dysregulated fibrinolysis precede the development of type 2 diabetes mellitus in a population-based study

Background

Diabetic patients experience stimulated coagulation and dysfibrinolysis, which is associated with an increased risk of cardiovascular events. This imbalance may precede the manifest diagnosis. We investigated whether elevated antigen levels of tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1), the tPA/PAI-1 complex, or von Willebrand Factor (VWF) precede type 2 diabetes mellitus (T2DM) diagnosis, and whether this elevation occurs before increased fasting plasma glucose (FPG) or 2-hour plasma glucose (2hPG) in individuals who later develop T2DM.

Methods

We conducted a prospective incident case-referent study within the Västerbotten Intervention Programme. Cardiovascular risk factor data as well as FPG and 2hPG and blood samples for future research were collected at a baseline health examination between 1989 and 2000, (n= 28 736). During follow-up in January 2001, 157 cases had developed T2DM. Referents without T2DM were matched for sex, age, and year of participation (n=277). Subgroup analysis was performed for cases with normal baseline glucose levels (FPG <6.1 mmol/L and 2hPG < 8.9 mmol/L) and cases with elevated levels (FPG 6.1-6.9 mmol/L and/or 2hPG 8.9-12.1 mmol/L).

Results

After adjusting for BMI, family history of diabetes, physical activity, smoking, systolic blood pressure and levels of C-reactive protein and triglycerides, independent associations were found between incident T2DM and elevated levels of tPA (OR=1.54, 95% CI 1.06-2.23), PAI-1 (OR=1.61, 95% CI 1.14-2.28), and tPA/PAI-1 complex (OR=2.45, 95% CI 1.56-3.84). In participants with normal glucose levels, PAI-1 (OR=2.06, 95% CI 1.10 - 3.86) exhibited an independent relationship with incident T2DM after the adjustments.

Conclusions

Elevated levels of fibrinolytic variables precede the manifestation of T2DM after adjusting for metabolic and cardiovascular risk factors and can be detected several years before changes in glucose tolerance.

The impact of leptin and adiponectin on incident type 2 diabetes is modified by sex and insulin resistance

BACKGROUND

Adiponectin and leptin and their ratio have been associated with incident type 2 diabetes (T2DM), although the data presented are conflicting and the populations studied have been small. In this large, prospective, nested, case referent study, we hypothesized that these associations are sex specific and may be modified by insulin resistance.

METHODS

Men and women aged 30-60 years with incident T2DM (n=640) and a prior health survey within the Västerbotten Intervention Programme (VIP) and matched referents (n=1564) were identified. Using conditional logistic regression analyses, we tested whether baseline plasma adiponectin and leptin levels and their ratio independently predicted incident T2DM, stratified for gender and insulin resistance.

RESULTS

Adjusted for traditional risk factors, fourth-quartile levels of adiponectin were associated with a reduced risk of T2DM in men [odds ratio (OR) 0.55 (0.36-0.86)] and women [OR 0.47 (0.27-0.83)]. Quartile four of the leptin/adiponectin ratio predicted T2DM in both men [OR 3.08 (1.68-5.67)] and women [OR 3.31 (1.56-7.03)], whereas quartile-four levels of leptin predicted T2DM only in men [OR 2.30 (1.32-4.02)]. When stratified for insulin sensitivity and adjusted for body mass index (BMI), log(e)-transformed leptin predicted T2DM in insulin-sensitive men [OR 1.56 (1.13-2.17)] but not in insulin-resistant men [OR 1.03 (0.76-1.39)]. The effect of adiponectin and the leptin/adiponectin ratio was not influenced by the insulin sensitivity status.

CONCLUSIONS

Leptin in men and adiponectin in both sexes were independent predictors of T2DM. The association was modified by the degree of insulin sensitivity. The leptin/adiponectin ratio may add predictive information beyond the separate hormones.

The Västerbotten Intervention Programme: background, design and implications

Background and objective

In Sweden, mortality from cardiovascular diseases (CVD) increased steadily during the 20th century and in the mid-1980s it was highest in the county of Västerbotten. Therefore, a community intervention programme was launched – the Västerbotten Intervention Programme (VIP) – with the aim of reducing morbidity and mortality from CVD and diabetes.

Design

The VIP was first developed in the small municipality of Norsjö in 1985. Subsequently, it was successively implemented across the county and is now integrated into ordinary primary care routines. A population-based strategy directed towards the public is combined with a strategy to reach all middle-aged persons individually at ages 40, 50 and 60 years, by inviting them to participate in systematic risk factor screening and individual counselling about healthy lifestyle habits. Blood samples for research purposes are stored at the Umeå University Medical Biobank.

Results

Overall, 113,203 health examinations have been conducted in the VIP and 6,500–7,000 examinations take place each year. Almost 27,000 subjects have participated twice. Participation rates have ranged between 48 and 67%. A dropout rate analysis in 1998 indicated only a small social selection bias. Cross-sectional, nested case-control studies and prospective studies have been based on the VIP data. Linkages between the VIP and local, regional and national databases provide opportunities for interdisciplinary research, as well as national and international collaborations on a wide range of disease outcomes. A large number of publications are based on data that are collected in the VIP, many of which also use results from analysed stored blood samples. More than 20 PhD theses have been based primarily on the VIP data.

Conclusions

The concept of the VIP, established as a collaboration between politicians and health care providers on the one hand and primary care, functioning as the operating machinery, and the public on the other, forms the basis for effective implementation and endurance over time. After more than 20 years of the VIP, there is a large comprehensive population-based database, a stable organisation to conduct health surveys and collect data, and a solid structure to enable widespread multidisciplinary and scientific collaborations.

Ethnic differences in the relationships of anthropometric measures to metabolic risk factors in Asian patients at risk of atherothrombosis: results from the REduction of Atherothrombosis for Continued Health (REACH) Registry

The aim of the study is to examine the relationships between 4 anthropometric indices and metabolic risk factors (hypertension, atherogenic dyslipidemia, and glucose intolerance) in different Asian ethnic groups of patients at risk of atherothrombosis. We analyzed the baseline data of 11 017 Asian patients with established atherothrombotic cardiovascular diseases or at least 3 atherothrombotic risk factors. In East and South Asians, the graded relationships of body mass index (BMI) with the presence of at least 2 metabolic risk factors remained significant after adjustment for waist circumference (top vs bottom quartile--East Asians: odds ratio, 2.02; 95% confidence interval, 1.67-2.45; South Asians: 3.24, 1.18-8.95), whereas the graded relationships of waist circumference decreased or became nonsignificant after adjustment for BMI (East Asians: 1.64, 1.35-1.99; South Asians: 0.68, 0.20-2.30). In Southeast Asian men, the graded relationship of waist circumference with metabolic risk factors (2.27, 1.42-3.63) was stronger than that of BMI (1.34, 0.84-2.12), whereas in Southeast Asian women, there was a trend toward a stronger association between BMI and metabolic risk factors. In East Asians and in Southeast Asian women, the waist-to-BMI ratio decreased with the number of metabolic risk factors. The optimal cutoff points for BMI and waist circumference with regard to the presence of at least 2 metabolic risk factors were lowest in East Asians (men: 24 kg/m(2) and 86 cm; women: 24 kg/m(2) and 82 cm). Our findings suggest that both BMI and waist circumference, rather than waist circumference alone, should be included in metabolic risk assessment in this high-risk multiethnic Asian population. Uniform anthropometric cutoff values for all Asian ethnic groups are not appropriate to assess obesity-related metabolic complications, even in patients with established atherothrombotic disease.

Psychometric testing of four transtheoretical model questionnaires for the behavior, completing health care proxies

The purpose of the study was to develop four questionnaires based on the transtheoretical model (TTM) to assess the behavior, completing a healthcare proxy (HCP). The aims were to (a) operationalize the four TTM constructs for completing a HCP and (b) evaluate the psychometric properties of the questionnaires. The questionnaires were constructed and content validity established using an expert panel. Internal consistency values for each questionnaire and subscales within each questionnaire were >.79. Confirmatory factor analysis provided evidence that decisional balance and the processes of change questionnaires each contained two factors. Our data support validity and reliability of the TTM questionnaires related to HCP completion.

The major inflammatory mediator interleukin-6 and obesity

Adipose tissue is one of the main sources of inflammatory mediators, with interleukin-6 (IL-6) among them. Although high systemic levels of inflammatory mediators are cachectogenic and/or anorexic, today it is a widely propagated thesis that in the background of obesity, a low level of chronic inflammation can be found, with IL-6 being one of the many suggested mediators. This paper reviews the studies describing elevated IL-6 levels in obese patients and the role of adipocytes and adipose-tissue macrophages in the production of IL-6. The secretion of IL-6 is regulated by several physiologic or pathologic factors: hormones, cytokines, diet, physical activity, stress, hypoxia, and others. Adipose tissue-derived IL-6 may have an effect on metabolism through several mechanisms, including adipose tissue-specific gene expression, triglyceride release, lipoprotein lipase downregulation, insulin sensitivity, and so on. Having a better understanding of these mechanisms may contribute to the prevention and treatment of obesity.

Hydrochlorothiazide, but not Candesartan, Aggravates Insulin Resistance and Causes Visceral and Hepatic Fat Accumulation

Treatment with angiotensin II receptor blockers is associated with lower risk for the development of type 2 diabetes mellitus compared with thiazide diuretics. The Mechanisms for the Diabetes Preventing Effect of Candesartan Study addressed insulin action and secretion and body fat distribution after treatment with candesartan, hydrochlorothiazide, and placebo. Twenty-six nondiabetic, abdominally obese, hypertensive patients were included in a multicenter 3-way crossover trial, and 22 completers (by predefined criteria; 10 men and 12 women) were included in the analyses. They underwent 12-week treatment periods with candesartan (C; 16 to 32 mg), hydrochlorothiazide (H; 25 to 50 mg), and placebo (P), respectively, and the treatment order was randomly assigned and double blinded. Intravenous glucose tolerance tests and euglycemic hyperinsulinemic (56 mU/m 2 per minute) clamps were performed. Intrahepatic and intramyocellular and extramyocellular lipid content and subcutaneous and visceral abdominal adipose tissue were measured using proton magnetic resonance spectroscopy and MRI. Insulin sensitivity (M-value) was reduced following H versus C and P (6.07±2.05, 6.63±2.04, and 6.90±2.10 mg/kg of body weight per minute, mean±SD; P ≤0.01). Liver fat content was higher ( P <0.05) following H than both P and C. The subcutaneous to visceral abdominal adipose tissue ratio was reduced following H versus C and P ( P <0.01). Glycosylated hemoglobin, alanine aminotransferase, aspartate aminotransferase, and high-sensitivity C-reactive protein levels were higher ( P <0.05) after H, but not C, versus P. There were no changes in body fat, intramyocellular lipid, extramyocellular lipid, or first-phase insulin secretion. Blood pressure was reduced similarly by C and H versus P. In conclusion, visceral fat redistribution, liver fat accumulation, low-grade inflammation, and aggravated insulin resistance were demonstrated after hydrochlorothiazide but not candesartan treatment. These findings can partly explain the diabetogenic potential of thiazides.