Incidence and predictors of type 2 diabetes among Koreans: A 12-year follow up of the Korean Genome and Epidemiology Study

Patients with diabetes in regions with population decline and likelihood of receiving diabetes management education and screenings for related complications in Korea

OBJECTIVE

Many municipal districts in Korea face population decline owing to overall population decreases and aging. We investigated the association between geographic rurality and likelihood of receiving diabetes management education and diabetic retinopathy and diabetes-related kidney disease screenings among adults with diabetes.

METHODS

Patient data were obtained from the 2021 Korea Community Health Survey (27,391 individuals; aged ≥19 years and physician-diagnosed with diabetes mellitus). Geographic rurality was categorized based on population decline as follows: with, at risk of, or without population decline. The association between geographic rurality and likelihood of receiving diabetes management education and diabetic retinopathy and diabetes-related kidney disease screenings was examined using multilevel logistic regression analyses.

RESULTS

Among 27,391 patients with diabetes, 31.1% received diabetes education; 40.0% and 46.4% were screened for diabetic retinopathy and diabetes-related kidney disease, respectively. Individuals residing in regions with population decline were less likely to receive diabetes education (odds ratio [OR] 0.62, 95% CI 0.50-0.75) and diabetic retinopathy (OR 0.79, 95% CI 0.70-0.90) and diabetes-related kidney disease (OR 0.64, 95% CI 0.55-0.75) screenings, as compared with their counterparts.

CONCLUSIONS

Our findings highlight the importance of increased monitoring and providing diabetes education and screenings for patients with diabetes living in rural areas.

Influence of Diabetes Mellitus and Smoking on Pro- and Anti-Inflammatory Cytokine Profiles in Gingival Crevicular Fluid

Smoking and diabetes mellitus have been recognized as significant modifying factors of the evolution of periodontitis, being considered at the moment as descriptive factors in the periodontitis grading system. The purpose of this study was to assess the consequence of smoking, type 2 diabetes, and the combination of these two factors on clinical periodontal parameters, on the levels of gingival crevicular fluid (GCF), and also on ratios of pro-inflammatory and anti-inflammatory cytokines by using a commercially available kit-based multiplex fluorescent immunoassay. The study was carried out on 124 volunteers (control (C) group = 29, diabetes mellitus (DM) group = 32, smoking (S) group = 31, and S + DM group = 32). Total mean bleeding on probing was significantly lower in the S and S + DM groups, compared to that of the other groups (p < 0.05). Total amounts of TGF-β, MIP-1α, IL-6, IL-2, and IL-17 were significantly increased in the periodontally healthy sites of diabetes patients (p < 0.05), compared to those of the controls. Systemically healthy smoking patients had higher values of GM-CSF, TGF-β, IL-4, TNF-α, IL-5, and IL-7, while diabetic smoking patients showed higher values of IL-4, TGF-β, and MIP-1α. In smoking and systemically healthy patients, IL-23, IL-7, and IL-12 showed increased concentrations, while concentrations of TGF-β, MIP-1α, IL-2, IL-7, IL-12, IL-17, IL-21, and IL-23 were higher in smoking DM patients. In conclusion, in our study, diabetes mellitus induced a general pro-inflammatory state, while smoking mainly stimulated immunosuppression in the periodontal tissues of periodontitis subjects.

Bidirectional associations between periodontal disease and systemic diseases: a nationwide population-based study in Korea

To evaluate the associations of periodontal disease (PD) with systemic diseases, including diabetes mellitus (DM) and cardiovascular disease (CVD), as well as the reciprocal association. The CVD included the cases of coronary heart disease and heart failure. A prospective study was conducted from 2007 to 2019 using linked data from three databases in Korea. Three separate study groups were formed to individually determine the risks of PD (n = 10,533), DM (n = 14,523) and CVD (n = 14,315). All diseases were confirmed based on physicians' diagnoses using medical records and self-reports. Cox proportional hazard regression was applied with 95% confidence intervals (CIs) to obtain hazard ratios (HRs). PD was significantly associated with an elevated risk of DM (HR [95% CI]: 1.22 [1.07-1.39]) after full adjustment for age, sex, lifestyle factors, body mass index, dental behaviour and CVD. PD was also found to increase the risk of CVD (1.27 [1.03-1.57]), whereas CVD increased the risk of PD (1.20 [1.09-1.32]) after full adjustment for other covariates including DM. This study found a bidirectional association between PD and CVD, as well as a positive association of PD with DM.

Differential contribution of alpha and beta cell dysfunction to impaired fasting glucose and impaired glucose tolerance

AIMS/HYPOTHESIS

People with isolated impaired fasting glucose (IFG) have normal beta cell function. We hypothesised that an increased glucose threshold for beta cell secretion explains IFG.

METHODS

We used graded glucose infusion to examine the relationship of insulin secretion rate (ISR) and glucagon secretion rate (GSR) with rising glucose. We studied 39 non-diabetic individuals (53 ± 2 years, BMI 30 ± 1 kg/m2), categorised by fasting glucose and glucose tolerance status. After an overnight fast, a variable insulin infusion was used to maintain glucose at ~4.44 mmol/l (07:00 to 08:30 hours). At 09:00 hours, graded glucose infusion commenced at 1 mg kg-1 min-1 and doubled every 60 min until 13:00 hours. GSR and ISR were calculated by nonparametric deconvolution from concentrations of glucagon and C-peptide, respectively.

RESULTS

The relationship of ISR with glucose was linear and the threshold for insulin secretion in isolated IFG did not differ from that in people with normal fasting glucose and normal glucose tolerance. GSR exhibited a single-exponential relationship with glucose that could be characterised by G50, the change in glucose necessary to suppress GSR by 50%. G50 was increased in IFG compared with normal fasting glucose regardless of the presence of impaired or normal glucose tolerance.

CONCLUSIONS/INTERPRETATION

These data show that, in non-diabetic humans, alpha cell dysfunction contributes to the pathogenesis of IFG independently of defects in insulin secretion. We also describe a new index that quantifies the suppression of glucagon secretion by glucose.

The association between dietary sodium intake and osteoporosis

The association of inadequate dietary sodium intake with bone mineral density (BMD) and the risk of osteoporosis is controversial. To find the association between low sodium diet and the risk of incipient osteoporosis, we performed a population-based cross-sectional analysis using Tanaka method for estimation 24-h urinary sodium excretion (e24hUNaE_Tanaka) as a candidate indicator of sodium intake. We identified 3869 participants without osteoporosis and classified them into quartiles according to their value of e24hUNaE_Tanaka. BMD was measured to find participants at risk of osteoporosis. Lower e24hUNaE_Tanaka was related to decreasing BMD of the distal radius. Multiple Cox-proportional hazard models demonstrated that e24hUNaE_Tanaka had an inverse association with the risk of osteoporosis (adjusted HR = 0.859, 95% CI = 0.751-0.982) and survival analysis revealed that the lowest quartile group had poor osteoporosis-free survival (P_Log-rank < 0.0001). Furthermore, our restricted cubic spline analysis revealed that the relationship between e24hUNaE_Tanaka and HR of osteoporosis was negative curvilinear in males and postmenopausal females and positive linear in premenopausal females. Our findings suggest that lower sodium intake was a significant predictor of incipient osteoporosis and there was wide variation in this relationship according to sex and female hormone status.

High incidence of type 2 diabetes in a population with normal range body mass index and individual prediction nomogram in Vietnam

AIMS

The study aimed at determining 5-year incidence and prediction nomogram for new-onset type 2 diabetes (T2D) in a middle-aged population in Vietnam.

METHODS

A population-based prospective study was designed to collect socio-economic, anthropometric, lifestyle and clinical data. Five-year T2D incidence was estimated and adjusted for age and sex. Hazard ratio (HR) for T2D was investigated using discrete-time proportional hazards model. T2D prediction model entering the most significant risk factors was developed using the multivariable logistic-regression algorithm. The corresponding prediction nomogram was constructed and checked for discrimination, calibration and clinical usefulness.

RESULTS

The age- and sex-adjusted incidence was 21.0 cases (95% CI: 12.2-40.0) per 1000 person-years in people with mean BMI of 22.2 (95% CI: 21.9-22.7 kg/m² ). The HRs (95% CI) for T2D were 1.14 (1.05-1.23) per 10 mmHg systolic blood pressure, 1.05 (1.03-1.08) per 1 cm waist circumference, 1.40 (1.13-1.73) per 1 mmol/L fasting blood glucose, 1.77 (1.15-2.71) per sleeping time (<6 h/day vs 6-7 h/day) and 2.12 (1.25-3.61) per residence (urban vs rural). The prediction nomogram for new-onset T2D had a good discrimination (area under curve: 0.711, 95% CI: 0.666-0.755) and fit calibration (mean absolute error: 0.009). For the predicted probability thresholds between 0.03 and 0.36, the nomogram showed a positive net benefit, without increasing the number of false positives.

CONCLUSION

This study highlighted an alarmingly high incidence of T2D in a middle-aged population with a normal range BMI in Vietnam. The individual prediction nomogram with decision curve analysis for new-onset T2D would be valuable for early detection, intervention and treatment of the condition.

Evidence From a Systematic Review and Meta-Analysis: Classical Impaired Glucose Tolerance Should Be Divided Into Subgroups of Isolated Impaired Glucose Tolerance and Impaired Glucose Tolerance Combined With Impaired Fasting Glucose, According to the Risk of Progression to Diabetes

BACKGROUND

The American Diabetes Association (ADA) 2003 diagnostic criteria divide impaired glucose tolerance (IGT) into isolated impaired glucose tolerance with normal fasting glucose (I-IGT, IGT+NFG) and impaired glucose tolerance combined with impaired fasting glucose (IGT+IFG), while the World Health Organization (WHO) 1999 criteria do not. The aim of this meta-analysis was to evaluate whether IGT should be divided into I-IGT (IGT+NFG) or IGT+IFG according to their risk of progression to type 2 diabetes.

METHODS

The MEDLINE and EMBASE were searched to identify prospective cohort studies published in English prior to April 18, 2020. Review Manager 5.3 was used to calculate the pooled risk ratios (RRs) and 95% confidence intervals (CIs) as summary statistics for each included study.

RESULTS

Sixteen eligible studies (n = 147,006) were included in the analysis. The subsequent incidence of type 2 diabetes was lower in the I-IGT (IGT+NFG) group than in the IGT+IFG group (0.45 [95% CI 0.37, 0.55] according to WHO 1999 criteria and 0.59 [95% CI 0.54, 0.66] according to ADA 2003 criteria). It was higher in the I-IFG, I-IGT (IGT+NFG), and IGT+IFG groups than in the normoglycemic group (95% CI of 5.53 [3.78, 8.08], 5.21 [3.70, 7.34], and 11.87 [7.33, 19.20] according to the WHO 1999 criteria and 95% CI of 2.66 [2.00, 3.54], 3.34 [2.81, 3.97], and 6.10 [4.72, 7.88] according to the ADA 2003 criteria). In general, the incidence of diabetes in the IGT+IFG group was the highest in the prediabetic population.

CONCLUSIONS

The present meta-analysis suggested that the established WHO diagnostic criteria for IGT should be revised to separately identify individuals with IGT+NFG or IGT+IFG.

Incidence and Risk Factors for Progression to Diabetes Mellitus: A Retrospective Cohort Study

(1) Objective: This study examined the incidence and risk factors contributing to the progression to diabetes mellitus (DM) in a seven-year follow-up study of non-diabetic National Health Examinees. (2) Methods: For this retrospective observational cohort study, we used two national representative databases: the National Health Screening (HEALS) database 2009 and the National Health Insurance Service (NHIS) database 2009-2015. The eligible subjects without DM with blood sugar levels of <126 mg/dL were selected using the HEALS database. The subsequent follow-up and clinical outcomes were evaluated using the NHIS database. Cox proportional hazard regression was applied to examine the effects of the covariates on progression to diabetes. (3) Results: Among those who took part in the national health screening in 2009, 4,205,006 subjects who met the eligibility criteria were selected. Of these, 587,015 were diagnosed with DM during the follow-up by 2015. The incidence of progression from non-diabetes to DM was 14.0%, whereas that from impaired fasting glucose (IFG) to DM was 21.9%. Compared to the normal group, the newly diagnosed DM group was more likely to comprise older, female, currently smoking, and high-risk drinking participants and participants with IFG, hypertension, dyslipidemia, and metabolic syndrome. (4) Conclusions: This epidemiological study in the Republic of Korea found risk factors similar to those of other studies, but the incidence of progression to DM was 22.8 per 1000 person-years, which is higher than that previously reported. Hence, more care is needed to prevent DM.

[Correlation of baseline serum 25-hydroxyvitamin D level with the risk of type 2 diabetes mellitus: a prospective cohort study]

OBJECTIVE

To investigate the correlation of baseline serum 25(OH) D level with the risk of type 2 diabetes mellitus (T2DM) and blood glucose control in diabetic patients among the middle-aged and elderly individuals in Chengguan District of Lanzhou, Gansu Province.

OBJECTIVE

Residents aged 40 to 75 years in Lanzhou were selected from the "REACTION" study conducted in 2011 and had been followed up since 2014. A total of 5044 subjects with complete data from the two surveys were analyzed. Participants were divided into Q1, Q2, Q3, and Q4 subgroups based on quartiles of serum 25(OH)D level for comparison of the incidence of T2DM and blood glucose control.

OBJECTIVE

Baseline 25(OH)D level was not found to correlate with FPG, 2h-PG or HbA1c levels among the residents (P>0.05). The participants were followed up for a mean of 3.4±0.6 years, and compared with those in Q1 group, the participants in Q2, Q3 and Q4 groups did not show significantly lowered risk of prediabetes or diabetes regardless of glucose tolerance status. Among the patients with T2DM, the compliance rate of glycemic control after the follow-up was significantly higher than that before the follow-up (63.4% vs 60.6%), and the levels of HbA1c, FPG, and 2h-PG decreased obviously after the follow-up. But compared with Q1 group, Q2, Q3 and Q4 groups showed no significant changes in glycemic control compliance rate or levels of HbA1c, FPG and 2h-PG after the follow-up (P>0.05).

OBJECTIVE

There is no evidence that baseline 25(OH)D levels are associated with the risk of diabetes and blood glucose control in patients with T2DM.

Diversity in the risk of type 2 diabetes associated with age, sex, and 1-h post-load plasma glucose levels in the Japanese population with prediabetes

AIMS

We investigated the risk of type 2 diabetes in the Japanese population with prediabetes, focusing on prediabetes categories, age- and sex-related differences, and plasma glucose levels during a 75-g oral glucose tolerance test.

METHODS

This retrospective cohort study included 11,414 participants (5330, 2560, 1501, and 2023 with normal fasting glucose/normal glucose tolerance, isolated impaired fasting glucose [IFG], isolated impaired glucose tolerance [IGT], and IFG plus IGT, respectively). The risk of type 2 diabetes was stratified by age and sex. Moreover, prediabetes was subdivided according to fasting plasma glucose (FPG) and 1-h post-load glucose levels.

RESULTS

Over a mean 6.3-year follow-up period, 1002 participants developed type 2 diabetes. The risk of type 2 diabetes was higher in isolated IFG than isolated IGT in elderly participants, but not in middle-aged participants. A higher risk was evident in isolated IFG in women, but not men. Moreover, about a 27- and 29-fold difference exists in men and women, respectively, in the risk of type 2 diabetes among the subdivided prediabetes categories.

CONCLUSION

The assessment of age and sex-differences and subdivided prediabetes categories based on FPG and 1-h post-load glucose levels may effectively evaluate the risk of type 2 diabetes, which displays marked diversity.

The mean of fasting, 1-h, and 2-h plasma glucose levels is superior to each separate index in predicting diabetes

AIMS

The fasting, 1-h, and 2-h plasma glucose (PG) levels during oral glucose tolerance test represent different glucose metabolic functions. We examined whether averaging these PG indices (GLU_M0.60.120) results in a better predictor of future type 2 diabetes (T2DM).

METHODS

7533 participants were followed up biannually for 12 years. Hazard ratios (HRs), area under the curve (AUC) of the receiver-operating characteristic, and the net reclassification index (NRI) for T2DM were calculated to compare the discriminative ability of GLU_M0.60.120 versus other PG indices.

RESULTS

The adjusted HRs and 95% confidence intervals for an increase in SD of GLU_M0.60.120 was 2.50 (2.36-2.65) and 1.88 (1.73-2.04) in T2DM-free and normal glucose tolerance (NGT) participants, respectively. The AUC of GLU_M0.60.120 was higher than that of fasting PG, 1-h, and 2-h PG values for T2DM-free (0.79 versus 0.67, 0.77, and 0.73) and NGT (0.73 versus 0.65, 0.72, and 0.61). The model using GLU_M0.60.120 improved the classification of the models with fasting PG, 1-h, and 2-h PG values (NRI: 0.369, 0.272, and 0.282 for T2DM-free and 0.249, 0.131, and 0.351 for NGT participants with all p < 0.001).

CONCLUSIONS

The mean of fasting, 1-h, and 2-h PG levels predicts future T2DM better than each index.

Epidemiology of Isolated Impaired Glucose Tolerance Among Adults Aged Above 50 Years in Rural China

INTRODUCTION

Isolated impaired glucose tolerance (i-IGT) is a subtype of prediabetes in which an individual demonstrates elevated 2-h post-glucose load glucose levels but normal fasting plasma glucose levels. However, few studies have explored the prevalence and risk factors of i-IGT among adults in rural China. Thus, we aimed to explore the prevalence and risk factors of i-IGT among adults ≥50 years old in a low-income, rural population in China.

MATERIALS AND METHODS

Individuals aged ≥50 years with normal fasting plasma glucose levels were included in the final analysis. Fasting and 2-h venous blood samples were collected to assess the selected parameter measurements.

RESULTS

A total of 2175 individuals were included in this study. The i-IGT prevalence was 22.9% and significantly higher among females than among males (P<0.05). Older age [odds ratio (OR), 1.606; 95% confidence interval (CI), 1.101-2.342; P=0.014), hypertension (OR, 1.554; 95% CI, 1.152-2.019; P=0.004), and central obesity (OR, 1.395; 95% CI, 1.099-1.771; P=0.006) were associated with i-IGT. Moreover, white blood cell (OR, 1.089; 95% CI, 1.009-1.175; P=0.029), high-sensitivity C-reactive protein (OR, 1.049; 95% CI, 1.020-1.078; P=0.001), serum uric acid (OR, 1.0003; 95% CI, 1.001-1.004; P=0.001), triglyceride (OR, 1.540; 95% CI, 1.105-2.147; P=0.011), and alanine aminotransferase (OR, 1.012; 95% CI, 1.004-1.021; P=0.004) levels were also linked to i-IGT in the analyzed population.

CONCLUSION

Health promotion education and a standardized approach to managing body weight, BP, and lipid and uric acid levels would benefit this low-income population in rural China for reducing the risk of cardiovascular disease.

Exploring the barriers of adherence to dietary recommendations among patients with type 2 diabetes: A qualitative study in Iran

Aims

Type 2 diabetes is a major global health concern, and its prevalence is rapidly increasing throughout the world. The present study was conducted to explore the experiences of patients and healthcare providers to identify the social barriers to patients' adherence to their recommended diet and thus help the design of future interventions.

Design

This study was conducted as a qualitative study with content analysis approach.

Methods

The present qualitative study was conducted from November 2016–July 2017. Data were collected through 38 unstructured in‐depth interviews with 33 T2D patients and their treatment supervisors and field notes. The interview transcripts were coded using the MAXQDA 10 software. To extract categories and themes, the thematic analysis approach was used. We followed the COREQ Checklist to ensure rigour in our study.

Results

The analysis of the study revealed the emergence of five categories of perceived barriers including social priorities and rivalries, family's food habits, poor social support, social impasses and dominant food patterns.

Mineral Intake Status of Community-Dwelling Elderly from Urban and Rural Areas of South Korea: A Cross-Sectional Study Based on Korean National Health and Nutrition Examination Survey, 2013~2016

We aimed to evaluate the intake of minerals (calcium, phosphorous, sodium, and potassium) in the urban and rural elderly and explore the adequacy of intake and food sources for each mineral using nationwide big data. The study used data from the Korea National Health and Nutrition Examination Survey (KNHANES) between 2013 and 2016. We analyzed 5292 elderly individuals that were aged 65 years and older (2271 men, 3021 women). Daily calcium, phosphorous, sodium, and potassium intake, and they were analyzed using the 24-h dietary recall method. Additionally, the adequacy of intake and food sources for each mineral was analyzed. Blood triglyceride level was significantly higher in rural elderly than in urban elderly. The intake of calcium and potassium per 1000 kcal of energy intake was significantly lower in the rural elderly, and the proportion of participants with calcium intake below the Estimated Average Requirement was significantly higher in the rural elderly than in the urban elderly. The intake of calcium, phosphorous, and potassium in the rural elderly was lower than that in the urban elderly. These results can be used as basic data when making social and environmental policies for the health of the elderly and when providing targeted dietary education for the management of chronic diseases for the elderly.

Systematic review with meta-analysis of the epidemiological evidence relating smoking to type 2 diabetes

BACKGROUND

Evidence relating tobacco smoking to type 2 diabetes has accumulated rapidly in the last few years, rendering earlier reviews considerably incomplete.

AIM

To review and meta-analyse evidence from prospective studies of the relationship between smoking and the onset of type 2 diabetes.

METHODS

Prospective studies were selected if the population was free of type 2 diabetes at baseline and evidence was available relating smoking to onset of the disease. Papers were identified from previous reviews, searches on Medline and Embase and reference lists. Data were extracted on a range of study characteristics and relative risks (RRs) were extracted comparing current, ever or former smokers with never smokers, and current smokers with non-current smokers, as well as by amount currently smoked and duration of quitting. Fixed- and random-effects estimates summarized RRs for each index of smoking overall and by various subdivisions of the data: Sex; continent; publication year; method of diagnosis; nature of the baseline population (inclusion/exclusion of pre-diabetes); number of adjustment factors; cohort size; number of type 2 diabetes cases; age; length of follow-up; definition of smoking; and whether or not various factors were adjusted for. Tests of heterogeneity and publication bias were also conducted.

RESULTS

The literature searches identified 157 relevant publications providing results from 145 studies. Fifty-three studies were conducted in Asia and 53 in Europe, with 32 in North America, and seven elsewhere. Twenty-four were in males, 10 in females and the rest in both sexes. Fifteen diagnosed type 2 diabetes from self-report by the individuals, 79 on medical records, and 51 on both. Studies varied widely in size of the cohort, number of cases, length of follow-up, and age. Overall, random-effects estimates of the RR were 1.33 [95% confidence interval (CI): 1.28-1.38] for current vs never smoking, 1.28 (95%CI: 1.24-1.32) for current vs non-smoking, 1.13 (95%CI: 1.11-1.16) for former vs never smoking, and 1.25 (95%CI: 1.21-1.28) for ever vs never smoking based on, respectively, 99, 156, 100 and 100 individual risk estimates. Risk estimates were generally elevated in each subdivision of the data by the various factors considered (exceptions being where numbers of estimates in the subsets were very low), though there was significant (P < 0.05) evidence of variation by level for some factors. Dose-response analysis showed a clear trend of increasing risk with increasing amount smoked by current smokers and of decreasing risk with increasing time quit. There was limited evidence of publication bias.

CONCLUSION

The analyses confirmed earlier reports of a modest dose-related association of current smoking and a weaker dose-related association of former smoking with type 2 diabetes risk.

Clinical Characteristics and Associated Risk Factors of Prediabetes in the Southwestern Region of Korea from 2010-2019

This study investigated the clinical characteristics and associated risk factors of prediabetes in the southwestern region of Korea. A total of 323 subjects from 13 prediabetes studies were included in the data analysis. Subjects with prediabetes were divided into the following subtypes: (1) normal glucose tolerance (NGT) with HbA1c 5.7%–6.4%; (2) isolated impaired fasting glucose (I-IFG); (3) isolated impaired glucose tolerance (I-IGT); and (4) combined I-IFG and I-IGT (C-IFG/IGT). Clinical and biochemical variables were compared among subtypes, and multivariate logistic regression analysis was used to identify risk factors for prediabetes subtypes. The overall proportion of subjects with NGT, I-IFG, I-IGT and C-IFG/IGT was 8.4%, 20.7%, 33.1% and 37.8%, respectively. In men, C-IFG/IGT was the most common subtype, while in women, I-IGT was the most common. The parameters related to dysglycemia, atherosclerosis and liver dysfunction were higher in subjects in the C-IFG/IGT subtype than in other subtypes. Multiple linear regression analysis revealed independent risk factors for increased FPG, 2h-PPG and HbA1c levels. This study identified the clinical features and independent risk factors for prediabetes subtypes.

The Effect of Metformin on Prognosis in Patients With Locally Advanced Gastric Cancer Associated With Type 2 Diabetes Mellitus

OBJECTIVES

This study examined the effect of metformin use on the prognosis of gastric cancer patients.

MATERIALS AND METHODS

The study population comprised 2187 patients who underwent curative gastrectomy for the treatment of gastric cancer. They were divided into 3 groups: metformin (n=103), non-metformin (n=139), and non-diabetes mellitus (DM) (n=1945) according to their history of type 2 DM and metformin use. Survival, disease recurrence, and the pathologic stage were analyzed.

RESULTS

Overall survival was better in the metformin group than in the non-DM group (P=0.005). Metformin use was an independent prognostic factor of overall survival, cancer recurrence, and peritoneal recurrence. An effect of metformin use was especially notable in patients with T4 or N0 disease.

CONCLUSIONS

Metformin improves the survival of patients with gastric cancer and type 2 DM.

Sex Differences in the Prevalence of and Risk Factors for Abnormal Glucose Regulation in Adults Aged 50 Years or Older With Normal Fasting Plasma Glucose Levels

AIMS

Abnormal glucose regulation, which can present as diabetes and prediabetes, has become one of the most common chronic conditions. However, sex differences in the prevalence of and factors associated with abnormal glucose regulation remain unclear. Thus, we aimed to explore sex differences in the prevalence of and factors associated with abnormal glucose regulation in low-income adults in China aged ≥50 years with normal fasting plasma glucose levels.

MATERIALS AND METHODS

A total of 2,175 individuals aged ≥50 years with normal fasting plasma glucose levels were recruited into this study. After an overnight fast of at least 10 h, individuals underwent an oral glucose tolerance test. Fasting and 2-h plasma glucose levels were measured to determine the state of glucose regulation.

RESULTS

Women were more likely than men to have isolated-impaired glucose tolerance (i-IGT) overall (24.7% vs 20.8%; P= 0.034), among individuals aged <65 years (21.7% vs 15.9%; P= 0.012). Among men, independent risk factors for i-IGT were an age of ≥65 years, hypertension, and high serum uric acid (SUA) and triglyceride levels; independent risk factors for diabetes mellitus (DM) were an age of ≥75 years and alcohol consumption. Among women, independent risk factors for i-IGT were central obesity and high levels of high-sensitivity C-reactive protein and SUA; independent risk factors for DM were low education and an elevated white blood cell count.

CONCLUSIONS

Our findings suggest that conventional cardiovascular disease risk factors (i.e., age, hypertension, and dyslipidemia) associated with high risk of developing DM in men, but poor life style (i.e., obesity) and low education attainment in women. It is necessary for delay or stopping the development of DM among low-income adults in China to implement the personalized scheme of prevention DM between men and women, especially highlight control the risk factors in young and middle aged women.

Lean body mass and risk of type 2 diabetes - a Danish cohort study

Purpose

Excess body fat is a commonly known risk factor for type 2 diabetes. However, whether lean body mass, or fat free mass, could have a protective effect against type 2 diabetes, remains unclear. The aim of this study was to explore the association between lean body mass, fat mass and type 2 diabetes.

Methods

This study used data from the Danish Diet, Cancer and Health cohort of 37,053 men and women, aged 50-64 years at baseline (1993-1997). The exposure was measurements of body composition using bioelectrical impedance analysis. Incident diabetes during follow-up was determined through linkage to the Danish National Diabetes Register. Cox proportional hazards regression analysis was used to estimate HR and 95%CI for the association between lean body mass and incident type 2 diabetes, with and without adjustment for fat mass. A sensitivity analysis was performed, excluding cases of incident type 2 diabetes within the first 2 years of follow-up.

Results

When adjusted for fat mass, the main analysis showed non-linear inverse association between lean body mass and risk of diabetes for men, but not for women. However, the sensitivity analysis found no association for either men or women.

Conclusions

Lean body mass was not associated with incident type 2 diabetes when excluding cases that may have been subclinical at baseline. The results imply that public health should focus on reduction of fat mass for diabetes prevention.

Intermediate hyperglycaemia to predict progression to type 2 diabetes (ELSA-Brasil): an occupational cohort study in Brazil

BACKGROUND

The burden of diabetes is increasing worldwide and diabetes can be prevented with intervention in people with impaired glucose tolerance (IGT). Intermediate hyperglycaemia defined without an oral glucose tolerance test as impaired fasting glucose (IFG) and high HbA_1c are also used to characterise risk. We aimed to assess the prognostic properties of five definitions of intermediate hyperglycaemia (also known as prediabetes) on the basis of their ability to predict who will progress to diabetes.

METHODS

The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) is an occupational cohort study of active or retired civil servants, aged 35-74 years, recruited from public universities and research institutes in six state capital cities in Brazil. We excluded participants who provided insufficient information to ascertain diabetes status, those without information on relevant covariates, and those with diabetes. We classified type 2 diabetes on the basis of self-report, medication use, measures of fasting plasma glucose (FPG), 2 h plasma glucose, and HbA_1c. We used five laboratory definitions of intermediate hyperglycaemia: IGT (2 h plasma glucose ≥7·8 mmol/L [≥140 mg/dL]); IFG based on American Diabetes Association (ADA) criteria (FPG ≥5·5 mmol/L [≥100 mg/dL]); IFG based on WHO criteria (FPG ≥6·1 mmol/L [≥110 mg/dL]); HbA_1c based on ADA criteria (HbA_1c ≥39 mmol/mol [5·7%]); and HbA_1c based on International Expert Committee criteria, IEC-HbA_1c, (HbA_1c ≥42 mmol/mol [6·0%]). We estimated risk of each definition using Cox regression and overall predictability (area under the receiver operating characteristic curve [AUC]) using logistic regression.

FINDINGS

We recruited 15 105 participants from Aug 18, 2008, to Dec 20, 2010, and followed up for a mean of 3·7 (SD 0·63) years. Diabetes incidence rate was 2·0 per 100 person-years (95% CI 1·8-2·1). Among the 11 199 eligible participants, 6563 (59%) presented with some form of intermediate hyperglycaemia. ADA-IFG (4870/11 199 [43·5%), IEC-HbA_1c (1005 [9·0%]), and ADA-HbA_1c (2299 [20·5%]) poorly predicted diabetes (3·5-3·6 per 100 person-years). WHO-IFG (1140 [10·2%]) and IGT (2245 [20·0%]) predicted greater conversion (7·5 per 100 person-years and 5·8 per 100 person-years, respectively). All definitions presented either low sensitivity or specificity. Combinations of tests improved prognostic properties, with the combination of IGT or WHO-IFG showing the best, but still insufficient, predictability (sensitivity 67·7%, 95% CI 64·5-70·1; specificity 77·9%, 77·1-78·7). The AUC for the three underlying glycaemic tests was 65·0% (95% CI 63·0-66·9) for HbA_1c, 74·6% (72·7-76·4) for FPG, and 77·1% (75·4-78·8) for 2 h plasma glucose, whereas the AUC for a score composed of clinical information was 71·6% (69·8-73·3). When this score was combined with results of an oral glucose tolerance test, the AUC reached 82·4% (80·9-83·9).

INTERPRETATION

IFG based on WHO criteria and IGT predict diabetes progression better than do the other three definitions of intermediate hyperglycaemia, but their sensitivity is low. IFG based on ADA criteria has better sensitivity than the others, but classifies almost half of adults as having intermediate hyperglycaemia and poorly predicts diabetes. Combining glycaemic results with clinical information improves prognostic properties of those at risk.

FUNDING

The Brazilian Ministry of Health (Science and Technology Department), the Brazilian Ministry of Science, Technology and Innovation (Financiadora de Estudos e Projetos and Conselho Nacional de Desenvolvimento Científico e Tecnológico), and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil (CAPES).

Hospital-Based Korean Diabetes Prevention Study: A Prospective, Multi-Center, Randomized, Open-Label Controlled Study

BACKGROUND

The prevalence of diabetes mellitus (DM) continues to increase, and the disease burden is the highest of any medical condition in Korea. However, large-scale clinical studies have not yet conducted to establish the basis for diabetes prevention in Korea.

METHODS

The hospital-based Korean Diabetes Prevention Study (H-KDPS) is a prospective, multi-center, randomized, open-label controlled study conducted at university hospitals for the purpose of gathering data to help in efforts to prevent type 2 DM. Ten university hospitals are participating, and 744 subjects will be recruited. The subjects are randomly assigned to the standard care group, lifestyle modification group, or metformin group, and their clinical course will be observed for 36 months.

RESULTS

All intervention methodologies were developed, validated, and approved by Korean Diabetes Association (KDA) multi-disciplinary team members. The standard control group will engage in individual education based on the current KDA guidelines, and the lifestyle modification group will participate in a professionally guided healthcare intervention aiming for ≥5% weight loss. The metformin group will begin dosing at 250 mg/day, increasing to a maximum of 1,000 mg/day. The primary endpoint of this study is the cumulative incidence of DM during the 3 years after randomization.

CONCLUSION

The H-KDPS study is the first large-scale clinical study to establish evidence-based interventions for the prevention of type 2 DM in Koreans. The evidence gathered by this study will be useful for enhancing the health of Koreans and improving the stability of the Korean healthcare system (Trial registration: CRIS KCT0002260, NCT02981121).

Inadequate fat or carbohydrate intake was associated with an increased incidence of type 2 diabetes mellitus in Korean adults: A 12-year community-based prospective cohort study

AIMS

Few studies have focused on the relationship between long-term fat intake and type 2 diabetes mellitus (T2D) risk in Asia where fat intake is relatively lower than the Western countries. We examined association of dietary fat and carbohydrate intake with incidence of T2D among Korean adults.

METHODS

Based on the data from the Korean Genome and Epidemiology Study, a total of 5595 adults aged 40-69 years without diabetes, cardiovascular diseases or any cancer at baseline were included. Dietary intake was measured by the validated semi-quantitative food frequency questionnaire. Cox proportional hazards regression analysis was used to calculate multivariable-adjusted relative risks (RRs) and 95% confidence intervals (CIs).

RESULTS

During a median follow-up of 138-months, 1010 cases of T2D were newly determined. The proportion of participants with fat intake less than 15% of total energy and with carbohydrate intake more than 65% of total energy was 59.0% and 88.9%, respectively. After adjusting for confounders, a very-low-fat intake was associated with an increased risk of T2D (RR of Quartile 1 vs Quartile 4, 1.74; 95% CI, 1.18-2.57; p for trend = 0.0058) in women. A very-high-carbohydrate intake was associated with an increased risk of T2D in men (RR of Quartile 4 vs Quartile 1, 1.54; 95% CI, 1.03-2.30; p for trend = 0.0124) and women (RR of Quartile 4 vs Quartile 1, 1.69; 95% CI, 1.08-2.67; p for trend = 0.0376).

CONCLUSIONS

A very-low-fat or very-high-carbohydrate intake may increase the T2D risk and might be associated with lower intake of various nutrients and unbalanced macronutrient composition.

Shared and unique risk factors for depression and diabetes mellitus in a longitudinal study, implications for prevention: an analysis of a longitudinal population sample aged ⩾45 years

OBJECTIVE

The objective of this study was to examine shared and unique risk factors for incident depression and diabetes mellitus in a national longitudinal population-based survey.

METHODS

Canadian National Population Health Survey (NPHS) longitudinal study was used. A subsample of the initial NPHS sample (n = 4845), free of depression or diabetes mellitus at baseline was tracked over a 10-year period. Univariate and multivariate modified Poisson regression models were used to estimate the relative risk (RR). Stratified analyses by sex were conducted to measure its moderating role. The goodness-of-fit of the various models was tested.

RESULTS

The cumulative incidence rate of major depressive disorder and incident diabetes mellitus at 10-year follow-up were 4.1% and 10.1% respectively. Hypertension, daily smoking, physical inactivity and being overweight or obese were shared risk factors for major depressive episode and diabetes mellitus. Being female, family stress, traumatic events, having any chronic disease or heart disease were uniquely associated with depression while increasing age and ethnicity (non-white) were unique risk factors for diabetes mellitus. Also, underweight, family stress, chronic disease, and heart disease were risk factors for major depressive disorder in both sexes. Six risk factors, age, ethnicity (non-white), high blood pressure, daily smoking, physical inactivity, and body mass index were associated with incident diabetes mellitus in both sexes.

CONCLUSION

We found common risk behaviors/conditions not specific to either diabetes mellitus or depression. These risks have also been implicated in the development of a variety of chronic diseases. These findings underline the importance of public health prevention programs targeting generic risk behaviors.

Smoking and diabetes: dangerous liaisons and confusing relationships

The combined harmful effects of cigarette smoking and hyperglycemia can accelerate vascular damage in patients with diabetes who smoke, as is well known. Can smoking cause diabetes? What are the effects of smoking on macro and microvascular complications? Now growing evidence indicates that regular smokers are at risk of developing incident diabetes. Since the prevalence rates of smoking in patients with diabetes are relatively similar to those of the general population, it is essential to address the main modifiable risk factor of smoking to prevent the onset of diabetes and delay the development of its complications. Quitting smoking shows clear benefits in terms of reducing or slowing the risk of cardiovascular morbidity and mortality in people with diabetes. Does quitting smoking decrease the incidence of diabetes and its progression? What are the effects of quitting smoking on complications? The current evidence does not seem to unequivocally suggest a positive role for quitting in patients with diabetes. Quitting smoking has also been shown to have a negative impact on body weight, glycemic control and subsequent increased risk of new-onset diabetes. Moreover, its role on microvascular complications of the disease is unclear. What are the current smoking cessation treatments, and which ones are better for patients with diabetes? Stopping smoking may be of value for diabetes prevention and management of the disease and its macrovascular and microvascular complications. Unfortunately, achieving long-lasting abstinence is not easy and novel approaches for managing these patients are needed. This narrative review examines the evidence on the impact of smoking and smoking cessation in patients with diabetes and particularly in type 2 diabetes mellitus and its complications. In addition, management options and potential future directions will be discussed.

The risk of type 2 diabetes mellitus according to 2-h plasma glucose level: The Korean Genome and Epidemiology Study (KoGES)

BACKGROUND

Although impaired glucose tolerance (IGT) is a definite risk factor for type 2 diabetes mellitus (T2DM), there is limited information about the risk stratification for incident T2DM within IGT group. Thus, we aimed to evaluate the incidental risk for T2DM according to 2-h plasma glucose (2-h PG) level of oral glucose tolerance test (OGTT) and phenotype of IGT.

METHODS

7654 Korean participated in the Korean Genome and Epidemiology Study (KoGES) were stratified by 2-h PG levels of OGTT, and followed up for 63,665 person-years. Cox proportional hazards model was used to calculate the hazard ratios (HRs) and 95% confidential interval (CI) for T2DM according to 2-h PG levels of OGTT with adjustment for multiple covariates. Subgroup analysis was performed by gender and the presence of impaired fasting glucose (IFG) or not.

RESULTS

Within IGT, the adjusted HRs for T2DM significantly increased proportionally to 2-h PG level [<140mg/dL: reference, 140-159mg/dL: 3.07 (2.67-3.54), 160-179mg/dL: 5.44 (CI 4.66-6.34), 180-199mg/dL: 7.91 (CI 6.53-9.59)]. IGT combined with IFG had the profoundly increased HRs than isolated IFG. Even within normal glucose tolerance (NGT), 2-h PG level≥120mg/dL had the higher risk for T2DM than other NGT groups. These associations were more dominant in male than female.

CONCLUSION

The highest level of 2h-PG (180-199mg/dL) in IGT and IGT with IFG were strong predictor for T2DM. 2-h PG of 120-139mg/dL was more significantly associated with T2DM within NGT, and male was more susceptible for T2DM than female.

Association of Thigh Muscle Mass with Insulin Resistance and Incident Type 2 Diabetes Mellitus in Japanese Americans

BACKGROUND

Skeletal muscle plays a major role in glucose metabolism. We investigated the association between thigh muscle mass, insulin resistance, and incident type 2 diabetes mellitus (T2DM) risk. In addition, we examined the role of body mass index (BMI) as a potential effect modifier in this association.

METHODS

This prospective study included 399 Japanese Americans without diabetes (mean age 51.6 years) who at baseline had an estimation of thigh muscle mass by computed tomography and at baseline and after 10 years of follow-up a 75-g oral glucose tolerance test and determination of homeostasis model assessment of insulin resistance (HOMA-IR). We fit regression models to examine the association between thigh muscle area and incidence of T2DM and change in HOMA-IR, both measured over 10 years.

RESULTS

Thigh muscle area was inversely associated with future HOMA-IR after adjustment for age, sex, BMI, HOMA-IR, fasting plasma glucose, total abdominal fat area, and thigh subcutaneous fat area at baseline (P=0.033). The 10-year cumulative incidence of T2DM was 22.1%. A statistically significant interaction between thigh muscle area and BMI was observed, i.e., greater thigh muscle area was associated with lower risk of incident T2DM for subjects at lower levels of BMI, but this association diminished at higher BMI levels.

CONCLUSION

Thigh muscle mass area was inversely associated with future insulin resistance. Greater thigh muscle area predicts a lower risk of incident T2DM for leaner Japanese Americans.

Increased Rates of Meal Absorption Do Not Explain Elevated 1-Hour Glucose in Subjects With Normal Glucose Tolerance

Context

In subjects with normal fasting glucose (NFG) and normal glucose tolerance (NGT), glucose concentrations >155 mg/dL 1 hour after 75 g of oral glucose predict increased risk of progression to diabetes. Recently, it has been suggested that the mechanism underlying this abnormality is increased gut absorption of glucose.

Objective

We sought to determine the rate of systemic appearance of meal-derived glucose in subjects classified by their 1-hour glucose after a 75-g oral glucose challenge.

Design

This was a cross-sectional study. Participating subjects underwent a 75-g oral glucose challenge and a labeled mixed meal test.

Setting

An inpatient clinical research unit at an academic medical center.

Participants

Thirty-six subjects with NFG/NGT participated in this study.

Interventions

Subjects underwent an oral glucose tolerance test. Subsequently, they underwent a labeled mixed meal to measure fasting and postprandial glucose metabolism.

Main Outcome Measures

We examined β-cell function and the rate of meal appearance (Meal R_a) in NFG/NGT subjects. Subsequently, we examined the relationship of peak postchallenge glucose with Meal R_a and indices of β-cell function.

Results

Peak glucose concentrations correlated inversely with β-cell function. No relationship of Meal R_a with peak postchallenge glucose concentrations was observed.

Conclusion

In subjects with NFG/NGT, elevated 1-hour peak postchallenge glucose concentrations reflect impaired β-cell function rather than increased systemic meal appearance.

Development of type 2 diabetes mellitus in people with intermediate hyperglycaemia

BACKGROUND

Intermediate hyperglycaemia (IH) is characterised by one or more measurements of elevated blood glucose concentrations, such as impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and elevated glycosylated haemoglobin A1c (HbA1c). These levels are higher than normal but below the diagnostic threshold for type 2 diabetes mellitus (T2DM). The reduced threshold of 5.6 mmol/L (100 mg/dL) fasting plasma glucose (FPG) for defining IFG, introduced by the American Diabetes Association (ADA) in 2003, substantially increased the prevalence of IFG. Likewise, the lowering of the HbA1c threshold from 6.0% to 5.7% by the ADA in 2010 could potentially have significant medical, public health and socioeconomic impacts.

OBJECTIVES

To assess the overall prognosis of people with IH for developing T2DM, regression from IH to normoglycaemia and the difference in T2DM incidence in people with IH versus people with normoglycaemia.

SEARCH METHODS

We searched MEDLINE, Embase, ClincialTrials.gov and the International Clinical Trials Registry Platform (ICTRP) Search Portal up to December 2016 and updated the MEDLINE search in February 2018. We used several complementary search methods in addition to a Boolean search based on analytical text mining.

SELECTION CRITERIA

We included prospective cohort studies investigating the development of T2DM in people with IH. We used standard definitions of IH as described by the ADA or World Health Organization (WHO). We excluded intervention trials and studies on cohorts with additional comorbidities at baseline, studies with missing data on the transition from IH to T2DM, and studies where T2DM incidence was evaluated by documents or self-report only.

DATA COLLECTION AND ANALYSIS

One review author extracted study characteristics, and a second author checked the extracted data. We used a tailored version of the Quality In Prognosis Studies (QUIPS) tool for assessing risk of bias. We pooled incidence and incidence rate ratios (IRR) using a random-effects model to account for between-study heterogeneity. To meta-analyse incidence data, we used a method for pooling proportions. For hazard ratios (HR) and odds ratios (OR) of IH versus normoglycaemia, reported with 95% confidence intervals (CI), we obtained standard errors from these CIs and performed random-effects meta-analyses using the generic inverse-variance method. We used multivariable HRs and the model with the greatest number of covariates. We evaluated the certainty of the evidence with an adapted version of the GRADE framework.

MAIN RESULTS

We included 103 prospective cohort studies. The studies mainly defined IH by IFG5.6 (FPG mmol/L 5.6 to 6.9 mmol/L or 100 mg/dL to 125 mg/dL), IFG6.1 (FPG 6.1 mmol/L to 6.9 mmol/L or 110 mg/dL to 125 mg/dL), IGT (plasma glucose 7.8 mmol/L to 11.1 mmol/L or 140 mg/dL to 199 mg/dL two hours after a 75 g glucose load on the oral glucose tolerance test, combined IFG and IGT (IFG/IGT), and elevated HbA1c (HbA1c5.7: HbA1c 5.7% to 6.4% or 39 mmol/mol to 46 mmol/mol; HbA1c6.0: HbA1c 6.0% to 6.4% or 42 mmol/mol to 46 mmol/mol). The follow-up period ranged from 1 to 24 years. Ninety-three studies evaluated the overall prognosis of people with IH measured by cumulative T2DM incidence, and 52 studies evaluated glycaemic status as a prognostic factor for T2DM by comparing a cohort with IH to a cohort with normoglycaemia. Participants were of Australian, European or North American origin in 41 studies; Latin American in 7; Asian or Middle Eastern in 50; and Islanders or American Indians in 5. Six studies included children and/or adolescents.Cumulative incidence of T2DM associated with IFG5.6, IFG6.1, IGT and the combination of IFG/IGT increased with length of follow-up. Cumulative incidence was highest with IFG/IGT, followed by IGT, IFG6.1 and IFG5.6. Limited data showed a higher T2DM incidence associated with HbA1c6.0 compared to HbA1c5.7. We rated the evidence for overall prognosis as of moderate certainty because of imprecision (wide CIs in most studies). In the 47 studies reporting restitution of normoglycaemia, regression ranged from 33% to 59% within one to five years follow-up, and from 17% to 42% for 6 to 11 years of follow-up (moderate-certainty evidence).Studies evaluating the prognostic effect of IH versus normoglycaemia reported different effect measures (HRs, IRRs and ORs). Overall, the effect measures all indicated an elevated risk of T2DM at 1 to 24 years of follow-up. Taking into account the long-term follow-up of cohort studies, estimation of HRs for time-dependent events like T2DM incidence appeared most reliable. The pooled HR and the number of studies and participants for different IH definitions as compared to normoglycaemia were: IFG5.6: HR 4.32 (95% CI 2.61 to 7.12), 8 studies, 9017 participants; IFG6.1: HR 5.47 (95% CI 3.50 to 8.54), 9 studies, 2818 participants; IGT: HR 3.61 (95% CI 2.31 to 5.64), 5 studies, 4010 participants; IFG and IGT: HR 6.90 (95% CI 4.15 to 11.45), 5 studies, 1038 participants; HbA1c5.7: HR 5.55 (95% CI 2.77 to 11.12), 4 studies, 5223 participants; HbA1c6.0: HR 10.10 (95% CI 3.59 to 28.43), 6 studies, 4532 participants. In subgroup analyses, there was no clear pattern of differences between geographic regions. We downgraded the evidence for the prognostic effect of IH versus normoglycaemia to low-certainty evidence due to study limitations because many studies did not adequately adjust for confounders. Imprecision and inconsistency required further downgrading due to wide 95% CIs and wide 95% prediction intervals (sometimes ranging from negative to positive prognostic factor to outcome associations), respectively.This evidence is up to date as of 26 February 2018.

AUTHORS' CONCLUSIONS

Overall prognosis of people with IH worsened over time. T2DM cumulative incidence generally increased over the course of follow-up but varied with IH definition. Regression from IH to normoglycaemia decreased over time but was observed even after 11 years of follow-up. The risk of developing T2DM when comparing IH with normoglycaemia at baseline varied by IH definition. Taking into consideration the uncertainty of the available evidence, as well as the fluctuating stages of normoglycaemia, IH and T2DM, which may transition from one stage to another in both directions even after years of follow-up, practitioners should be careful about the potential implications of any active intervention for people 'diagnosed' with IH.

Development and Validation of the Korean Diabetes Risk Score: A 10-Year National Cohort Study

BACKGROUND

A diabetes risk score in Korean adults was developed and validated.

METHODS

This study used the National Health Insurance Service-National Health Screening Cohort (NHIS-HEALS) of 359,349 people without diabetes at baseline to derive an equation for predicting the risk of developing diabetes, using Cox proportional hazards regression models. External validation was conducted using data from the Korean Genome and Epidemiology Study. Calibration and discrimination analyses were performed separately for men and women in the development and validation datasets.

RESULTS

During a median follow-up of 10.8 years, 37,678 cases (event rate=10.4 per 1,000 person-years) of diabetes were identified in the development cohort. The risk score included age, family history of diabetes, alcohol intake (only in men), smoking status, physical activity, use of antihypertensive therapy, use of statin therapy, body mass index, systolic blood pressure, total cholesterol, fasting glucose, and γ glutamyl transferase (only in women). The C-statistics for the models for risk at 10 years were 0.71 (95% confidence interval [CI], 0.70 to 0.73) for the men and 0.76 (95% CI, 0.75 to 0.78) for the women in the development dataset. In the validation dataset, the C-statistics were 0.63 (95% CI, 0.53 to 0.73) for men and 0.66 (95% CI, 0.55 to 0.76) for women.

CONCLUSION

The Korean Diabetes Risk Score may identify people at high risk of developing diabetes and may be an effective tool for delaying or preventing the onset of condition as risk management strategies involving modifiable risk factors can be recommended to those identified as at high risk.

The risk of type 2 diabetes mellitus according to the categories of body mass index: the Korean Genome and Epidemiology Study (KoGES)

AIMS

Obesity is an established risk factor for type 2 diabetes mellitus (T2DM). However, there is limited information on the pattern of relationship between the risk for T2DM and body mass index (BMI) categories including underweight and overweight. Thus, this study was to evaluate the risk of T2DM according to BMI categories defined by Asian-specific cutoff of BMI.

METHODS

7660 non-diabetic Koreans were grouped into five BMI categories (underweight, normal, overweight, obese and severe obese) defined by Asian-specific cutoff of BMI and followed up for 10 years to monitor the development of T2DM. With a reference of normal BMI group, Cox proportional hazards assumption was used to calculate hazard ratios (HRs) and their 95% confidence intervals for T2DM in five groups. Subgroup analysis was conducted by gender and age (40-59 years and 60-69 years).

RESULTS

Baseline mean value of metabolic factors like fasting glucose, HOMA-IR, total cholesterol and the proportion of impaired fasting glucose increased proportionally to the level of BMI categories. Underweight group had the higher proportion of impaired glucose tolerance than normal and overweight group. In all subgroups, underweight, overweight, obese and severe obese group had the higher HRs for T2DM than normal group, but statistical significance was only found in overweight, obese and severe obese group.

CONCLUSIONS

The risk of T2DM tends to increase proportionally to the level of BMI categories from overweight to severe obese group. Further studies should be considered to identify the incidental relationship between underweight and T2DM.

The influence of prehypertension, hypertension, and glycated hemoglobin on the development of type 2 diabetes mellitus in prediabetes: the Korean Genome and Epidemiology Study (KoGES)

BACKGROUND

It has been reported that elevated blood pressure (BP) was significantly associated with the increased risk for type 2 diabetes mellitus (T2DM). However, there is still limited information about the influence of BP on the risk for T2DM across the level of glycated hemoglobin (HbA1c).

METHOD

In a cohort of the Korean Genome and Epidemiology Study (KoGES), 2830 non-diabetic Korean adults with prediabetes defined by HbA1c level of 5.7-6.4% were followed-up for 10 years. Multivariate cox proportional hazards assumption was used to assess the risk for T2DM according to the baseline BP categories (normal, prehypertension and hypertension) and HbA1c level (low: 5.7-5.9% and high: 6.0-6.4%).

RESULTS

The risk for T2DM significantly increased proportionally to BP categories (adjusted HR; reference in normal BP, 1.32 [1.10-1.59] in prehypertension and 1.61 [1.35-1.92] in hypertension). Subgroup analysis indicated that individuals with high HbA1c had the higher risk for T2DM than individuals with low HbA1c regardless of BP. Additionally, combined presence of hypertension and high HbA1c had the highest risk for T2DM (adjusted HR: 3.82 [3.00-4.87]). In each systolic and diastolic BP level, the risk for T2DM significantly increased from systolic BP ≥ 130 mmHg (adjusted HRs: 1.39 ([1.15-1.71]) and diastolic BP ≥ 80 mmHg (adjusted HRs: 1.30 ([1.07-1.58]).

CONCLUSION

BP and HbA1c may be useful tools in identifying individuals with prediabetes more potentially predisposed to T2DM. Prospective studies should be considered to examine whether controlling BP actually lowers the risk for T2DM.

Built environmental characteristics and diabetes: a systematic review and meta-analysis

BACKGROUND

The built environment influences behaviour, like physical activity, diet and sleep, which affects the risk of type 2 diabetes mellitus (T2DM). This study systematically reviewed and meta-analysed evidence on the association between built environmental characteristics related to lifestyle behaviour and T2DM risk/prevalence, worldwide.

METHODS

We systematically searched PubMed, EMBASE.com and Web of Science from their inception to 6 June 2017. Studies were included with adult populations (>18 years), T2DM or glycaemic markers as outcomes, and physical activity and/or food environment and/or residential noise as independent variables. We excluded studies of specific subsamples of the population, that focused on built environmental characteristics that directly affect the cardiovascular system, that performed prediction analyses and that do not report original research. Data appraisal and extraction were based on published reports (PROSPERO-ID: CRD42016035663).

RESULTS

From 11,279 studies, 109 were eligible and 40 were meta-analysed. Living in an urban residence was associated with higher T2DM risk/prevalence (n = 19, odds ratio (OR) = 1.40; 95% CI, 1.2-1.6; I² = 83%) compared to living in a rural residence. Higher neighbourhood walkability was associated with lower T2DM risk/prevalence (n = 8, OR = 0.79; 95% CI, 0.7-0.9; I² = 92%) and more green space tended to be associated with lower T2DM risk/prevalence (n = 6, OR = 0.90; 95% CI, 0.8-1.0; I² = 95%). No convincing evidence was found of an association between food environment with T2DM risk/prevalence.

CONCLUSIONS

An important strength of the study was the comprehensive overview of the literature, but our study was limited by the conclusion of mainly cross-sectional studies. In addition to other positive consequences of walkability and access to green space, these environmental characteristics may also contribute to T2DM prevention. These results may be relevant for infrastructure planning.

Effectiveness of educational intervention based on psychological factors on achieving health outcomes in patients with type 2 diabetes

BACKGROUND

Managing type 2 diabetes (T2D) is assumed to be heavily dependent on patients' active participation in their own self-care behaviors including prescribed diets.

OBJECTIVES

The purpose of the present study was to investigate the effectiveness of educational intervention based on psychological factors on nutritional behaviors as well as levels of fasting blood sugar (FBS) and glycated hemoglobin (HbA1c) in patients with T2D referring to diabetes clinics and healthcare centers in the city of Izeh, Iran.

METHODS

A total number of 145 patients were recruited in this clinical trial and then randomly assigned to two groups of intervention (n = 73 individuals) and control (n = 72 individuals). After that, a researcher-made multi-part questionnaire including a demographic characteristics information form, a nutritional perceptions and beliefs questionnaire; a scale measuring fears, concerns, and discomforts associated with diabetic diet, as well as the valid and reliable Perceived Dietary Adherence Questionnaire were used to collect the required data before and 3 months after the completion of the educational intervention. To this end, the patients in the intervention group attended an educational program for eight sessions but the individuals in the control group only received routine services. Data analysis was also conducted using the SPSS Statistics (Version 18) and via descriptive and inferential statistics.

RESULTS

The findings revealed that the mean scores of the sub-groups of nutritional perceptions and beliefs (but not exaggerated ones) in the patients assigned to the intervention group were significantly higher than those in the control group after 3 months (p = 0.001). As well, the mean scores of the sub-groups of fears, concerns, and discomforts in patients as well as exaggerated beliefs witnessed a significant decrease in the intervention group compared to those in the control group (p = 0.001) 3 months after the educational intervention. Furthermore, the mean scores of adherence to a healthy diet in the intervention group had significantly increased compared to those in the control group. There was correspondingly a significant descending trend in the average levels of fasting blood sugar (FBS) and glycated hemoglobin (HbA1c) in the intervention group compared to those obtained in the control group (p = 0.001).

CONCLUSION

The results of this study shed light on the importance of the effectiveness of psychological factors on achieving health outcomes in patients with type 2 diabetes (T2D). Moreover, a new combination of diet-related psychological factors in patients with diabetes was introduced in the present study.Trial registration IRCT. IRCT20180308039008N1. Registered 15 April 2018, http://www.irct.ir.

Cigarette Smoking, Diabetes, and Diabetes Complications: Call for Urgent Action

PURPOSE OF REVIEW

This review aimed to examine the latest evidence linking cigarette smoking and cessation to risk of incident diabetes and its complications.

RECENT FINDINGS

Abundant evidence has demonstrated that smoking is associated with increased risk of type 2 diabetes and cardiovascular disease among diabetic patients, while its relationship with microvascular complications is more limited to diabetic nephropathy and neuropathy in type 1 diabetes. In addition, diabetes risk remains high in the short term after smoking cessation, while it reduces gradually in the long term. Risk of cardiovascular complications also substantially decreases after quitting smoking, but results for microvascular complications are not consistent. Smoking is associated with increased risks of incident diabetes in the general population and cardiovascular complications among diabetic patients. Although the short-term post-cessation diabetes risk needs to be acknowledged, this review calls for urgent action to implement population-wide policies and individual pharmaceutical and lifestyle interventions (if evidence accumulated in future) to aid smoking cessation and prevent diabetes and its complications.

Assessing Health Impacts of Pictorial Health Warning Labels on Cigarette Packs in Korea Using DYNAMO-HIA

OBJECTIVES

This study aimed to predict the 10-year impacts of the introduction of pictorial warning labels (PWLs) on cigarette packaging in 2016 in Korea for adults using DYNAMO-HIA.

METHODS

In total, four scenarios were constructed to better understand the potential health impacts of PWLs: two for PWLs and the other two for a hypothetical cigarette tax increase. In both policies, an optimistic and a conservative scenario were constructed. The reference scenario assumed the 2015 smoking rate would remain the same. Demographic data and epidemiological data were obtained from various sources. Differences in the predicted smoking prevalence and prevalence, incidence, and mortality from diseases were compared between the reference scenario and the four policy scenarios.

RESULTS

It was predicted that the optimistic PWLs scenario (PWO) would lower the smoking rate by 4.79% in males and 0.66% in females compared to the reference scenario in 2017. However, the impact on the reduction of the smoking rate was expected to diminish over time. PWO will prevent 85 238 cases of diabetes, 67 948 of chronic obstructive pulmonary disease, 31 526 of ischemic heart disease, 21 036 of lung cancer, and 3972 prevalent cases of oral cancer in total over the 10-year span due to the reductions in smoking prevalence. The impacts of PWO are expected to be between the impact of the optimistic and the conservative cigarette tax increase scenarios. The results were sensitive to the transition probability of smoking status.

CONCLUSIONS

The introduction of PWLs in 2016 in Korea is expected reduce smoking prevalence and disease cases for the next 10 years, but regular replacements of PWLs are needed for persistent impacts.