The Singapore impaired glucose tolerance follow-up study: does the ticking clock go backward as well as forward?

Greater exposure to PM2.5 and PM10 was associated with lower corneal nerve measures: the Maastricht study - a cross-sectional study

BACKGROUND

Epidemiological and toxicological studies indicate that increased exposure to air pollutants can lead to neurodegenerative diseases. To further confirm this relationship, we evaluated the association between exposure to ambient air pollutants and corneal nerve measures as a surrogate for neurodegeneration, using corneal confocal microscopy.

METHODS

We used population-based observational cross-sectional data from The Maastricht Study including N = 3635 participants (mean age 59.3 years, 51.6% were women, and 19.9% had type 2 diabetes) living in the Maastricht area. Using the Geoscience and hEalth Cohort COnsortium (GECCO) data we linked the yearly average exposure levels of ambient air pollutants at home address-level [particulate matter with diameters of ≤ 2.5 µm (PM2.5), and ≤ 10.0 µm (PM10), nitrogen dioxide (NO2), and elemental carbon (EC)]. We used linear regression analysis to study the associations between Z-score for ambient air pollutants concentrations (PM2.5, PM10, NO2, and EC) and Z-score for individual corneal nerve measures (corneal nerve bifurcation density, corneal nerve density, corneal nerve length, and fractal dimension).

RESULTS

After adjustment for potential confounders (age, sex, level of education, glucose metabolism status, corneal confocal microscopy lag time, inclusion year of participants, smoking status, and alcohol consumption), higher Z-scores for PM2.5 and PM10 were associated with lower Z-scores for corneal nerve bifurcation density, nerve density, nerve length, and nerve fractal dimension [stβ (95% CI): PM2.5 -0.10 (-0.14; -0.05), -0.04 (-0.09; 0.01), -0.11 (-0.16; -0.06), -0.20 (-0.24; -0.15); and PM10 -0.08 (-0.13; -0.03), -0.04 (-0.09; 0.01), -0.08 (-0.13; -0.04), -0.17 (-0.21; -0.12)], respectively. No associations were found between NO2 and EC and corneal nerve measures.

CONCLUSIONS

Our population-based study demonstrated that exposure to higher levels of PM2.5 and PM10 are associated with higher levels of corneal neurodegeneration, estimated from lower corneal nerve measures. Our results suggest that air pollution may be a determinant for neurodegeneration assessed in the cornea and may impact the ocular surface health as well.

(Pre)diabetes and a higher level of glycaemic measures are continuously associated with corneal neurodegeneration assessed by corneal confocal microscopy: the Maastricht Study

AIMS/HYPOTHESIS

To assess the associations between glucose metabolism status and a range of continuous measures of glycaemia with corneal nerve fibre measures, as assessed using corneal confocal microscopy.

METHODS

We used population-based observational cross-sectional data from the Maastricht Study of N=3471 participants (mean age 59.4 years, 48.4% men, 14.7% with prediabetes, 21.0% with type 2 diabetes) to study the associations, after adjustment for demographic, cardiovascular risk and lifestyle factors, between glucose metabolism status (prediabetes and type 2 diabetes vs normal glucose metabolism) plus measures of glycaemia (fasting plasma glucose, 2 h post-load glucose, HbA1c, skin autofluorescence [SAF] and duration of diabetes) and composite Z-scores of corneal nerve fibre measures or individual corneal nerve fibre measures (corneal nerve bifurcation density, corneal nerve density, corneal nerve length and fractal dimension). We used linear regression analysis, and, for glucose metabolism status, performed a linear trend analysis.

RESULTS

After full adjustment, a more adverse glucose metabolism status was associated with a lower composite Z-score for corneal nerve fibre measures (β coefficients [95% CI], prediabetes vs normal glucose metabolism -0.08 [-0.17, 0.03], type 2 diabetes vs normal glucose metabolism -0.14 [-0.25, -0.04]; linear trend analysis showed a p value of 0.001), and higher levels of measures of glycaemia (fasting plasma glucose, 2 h post-load glucose, HbA1c, SAF and duration of diabetes) were all significantly associated with a lower composite Z-score for corneal nerve fibre measures (per SD: -0.09 [-0.13, -0.05], -0.07 [-0.11, -0.03], -0.08 [-0.11, -0.04], -0.05 [-0.08, -0.01], -0.09 [-0.17, -0.001], respectively). In general, directionally similar associations were observed for individual corneal nerve fibre measures.

CONCLUSIONS/INTERPRETATION

To our knowledge, this is the first population-based study to show that a more adverse glucose metabolism status and higher levels of glycaemic measures were all linearly associated with corneal neurodegeneration after adjustment for an extensive set of potential confounders. Our results indicate that glycaemia-associated corneal neurodegeneration is a continuous process that starts before the onset of type 2 diabetes. Further research is needed to investigate whether early reduction of hyperglycaemia can prevent corneal neurodegeneration.

Assessing Elevated Blood Glucose Levels Through Blood Glucose Evaluation and Monitoring Using Machine Learning and Wearable Photoplethysmography Sensors: Algorithm Development and Validation

BACKGROUND

Diabetes mellitus is the most challenging and fastest-growing global public health concern. Approximately 10.5% of the global adult population is affected by diabetes, and almost half of them are undiagnosed. The growing at-risk population exacerbates the shortage of health resources, with an estimated 10.6% and 6.2% of adults worldwide having impaired glucose tolerance and impaired fasting glycemia, respectively. All current diabetes screening methods are invasive and opportunistic and must be conducted in a hospital or laboratory by trained professionals. At-risk participants might remain undetected for years and miss the precious time window for early intervention to prevent or delay the onset of diabetes and its complications.

OBJECTIVE

We aimed to develop an artificial intelligence solution to recognize elevated blood glucose levels (≥7.8 mmol/L) noninvasively and evaluate diabetic risk based on repeated measurements.

METHODS

This study was conducted at KK Women's and Children's Hospital in Singapore, and 500 participants were recruited (mean age 38.73, SD 10.61 years; mean BMI 24.4, SD 5.1 kg/m2). The blood glucose levels for most participants were measured before and after consuming 75 g of sugary drinks using both a conventional glucometer (Accu-Chek Performa) and a wrist-worn wearable. The results obtained from the glucometer were used as ground-truth measurements. We performed extensive feature engineering on photoplethysmography (PPG) sensor data and identified features that were sensitive to glucose changes. These selected features were further analyzed using an explainable artificial intelligence approach to understand their contribution to our predictions.

RESULTS

Multiple machine learning models were trained and assessed with 10-fold cross-validation, using participant demographic data and critical features extracted from PPG measurements as predictors. A support vector machine with a radial basis function kernel had the best detection performance, with an average accuracy of 84.7%, a sensitivity of 81.05%, a specificity of 88.3%, a precision of 87.51%, a geometric mean of 84.54%, and F score of 84.03%.

CONCLUSIONS

Our findings suggest that PPG measurements can be used to identify participants with elevated blood glucose measurements and assist in the screening of participants for diabetes risk.

Incidence of depression in patients with cardiovascular disease and type 2 diabetes: a nationwide cohort study

BACKGROUND

Estimating how type 2 diabetes (T2D) affects the rate of depression in cardiovascular disease (CVD) can help identify high-risk patients. The aim is to investigate how T2D affects the rate of depression according to specific subtypes of CVD.

METHODS

Incident CVD patients, free of psychiatric disease, with and without T2D, were included from nationwide registries between 2010 and 2020. We followed patients from CVD diagnosis until the first occurrence of depression, emigration, death, 5 years, or end of study (December 31, 2021). We used time-dependent Poisson regression to estimate the incidence rates and rate ratios (IRR) of depression following subtypes of CVD with and without T2D. The model included age, sex, comorbidities, calendar year, T2D duration, educational level, and living situation as covariates.

RESULTS

A total of 165,096 patients were included; 45,845 had a myocardial infarction (MI), 63,691 had a stroke, 19,959 had peripheral artery disease (PAD), 35,568 had heart failure (HF), and 979 were diagnosed with 2 or more CVD subtypes (= > 2 CVD's). Baseline T2D in each CVD subtype ranged from 11 to 17%. The crude incidence rate of depression per 1000 person-years (95% confidence intervals) was: MI + T2D: 131.1 (109.6;155.6), MI: 82.1 (65.3;101.9), stroke + T2D: 287.4 (255.1;322.6), stroke: 222.4(194.1;253.6), PAD + T2D: 173.6 (148.7;201.4), PAD:137.5 (115.5;162.5), HF + T2D: 244.3 (214.6;276.9), HF: 199.2 (172.5;228.9), =  > 2 CVD's + T2D: 427.7 (388.1;470.2), =  > 2 CVD's: 372.1 (335.2;411.9). The adjusted IRR of depression in MI, stroke, PAD, HF, and =  > 2 CVD's with T2D compared to those free of T2D was: 1.29 (1.23;1.35), 1.09 (1.06;1.12), 1.18 (1.13;1.24), 1.05 (1.02;1.09), and 1.04 (0.85;1.27) (p-value for interaction < 0.001).

CONCLUSION

The presence of T2D increased the rate of depression differently among CVD subtypes, most notable in patients with MI and PAD.

Retinal Functional and Structural Neural Indices: Potential Biomarkers for the Monitoring of Cerebral Neurodegeneration: The Maastricht Study

BACKGROUND

If retinal indices of neurodegeneration are to be biomarkers for the monitoring of cerebral neurodegeneration, it is important to establish whether potentially modifiable risk factors for dementia are associated with retinal neurodegenerative changes.

OBJECTIVE

To study associations of dementia risk factors with retinal sensitivity, an index of retinal neural function, and retinal nerve fiber layer (RNFL) thickness, an index of retinal neural structure.

METHODS

We used cross-sectional data from The Maastricht Study (up to 5,666 participants, 50.5% men, mean age 59.7), and investigated associations with regression analyses (adjusted for potential confounders).

RESULTS

Most risk factors under study (i.e., hyperglycemia, unhealthy diet, lower cardiorespiratory fitness, smoking, alcohol consumption, and hypertension) were significantly associated with lower retinal sensitivity and lower RNFL thickness.

CONCLUSION

Findings of this population-based study support the concept that retinal neural indices may be biomarkers for the monitoring of therapeutic strategies that aim to prevent early-stage cerebral neurodegeneration and, ultimately, dementia.

(Pre)diabetes, glycemia, and daily glucose variability are associated with retinal nerve fiber layer thickness in The Maastricht Study

Retinopathy and neuropathy in type 2 diabetes are preceded by retinal nerve fibre layer (RNFL) thinning, an index of neurodegeneration. We investigated whether glucose metabolism status (GMS), measures of glycaemia, and daily glucose variability (GV) are associated with RNFL thickness over the entire range of glucose tolerance. We used cross-sectional data from The Maastricht Study (up to 5455 participants, 48.9% men, mean age 59.5 years and 22.7% with type 2 diabetes) to investigate the associations of GMS, measures of glycaemia (fasting plasma glucose [FPG], 2-h post-load glucose [2-h PG], HbA1c, advanced glycation endproducts [AGEs] assessed as skin autofluorescence [SAF]) and indices of daily GV (incremental glucose peak [IGP] and continuous glucose monitoring [CGM]-assessed standard deviation [SD]) with mean RNFL thickness. We used linear regression analyses and, for GMS, P for trend analyses. We adjusted associations for demographic, cardiovascular risk and lifestyle factors, and, only for measures of GV, for indices of mean glycaemia. After full adjustment, type 2 diabetes and prediabetes (versus normal glucose metabolism) were associated with lower RNFL thickness (standardized beta [95% CI], respectively - 0.16 [- 0.25; - 0.08]; - 0.05 [- 0.13;  0.03]; P_trend = 0.001). Greater FPG, 2-h PG, HbA1c, SAF, IGP, but not CGM-assessed SD, were also associated with lower RNFL thickness (per SD, respectively - 0.05 [- 0.08; - 0.01]; - 0.06 [- 0.09; - 0.02]; - 0.05 [- 0.08; - 0.02]; - 0.04 [- 0.07; - 0.01]; - 0.06 [- 0.12; - 0.01]; and - 0.07 [- 0.21; 0.07]). In this population-based study, a more adverse GMS and, over the entire range of glucose tolerance, greater glycaemia and daily GV were associated with lower RNFL thickness. Hence, early identification of individuals with hyperglycaemia, early glucose-lowering treatment, and early monitoring of daily GV may contribute to the prevention of RNFL thinning, an index of neurodegeneration and precursor of retinopathy and neuropathy.

Baseline characteristics of participants in the Pre-Diabetes Interventions and Continued Tracking to Ease-out Diabetes (Pre-DICTED) Program

OBJECTIVE

The Pre-Diabetes Interventions and Continued Tracking to Ease-out Diabetes (Pre-DICTED) Program is a diabetes prevention trial comparing the diabetes conversion rate at 3 years between the intervention group, which receives the incentivized lifestyle intervention program with stepwise addition of metformin, and the control group, which receives the standard of care. We describe the baseline characteristics and compare Pre-DICTED participants with other diabetes prevention trials cohort.

RESEARCH DESIGN AND METHODS

Participants were aged between 21 and 64 years, overweight (body mass index (BMI) ≥23.0 kg/m2), and had pre-diabetes (impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT)).

RESULTS

A total of 751 participants (53.1% women) were randomized. At baseline, mean (SD) age was 52.5 (8.5) years and mean BMI (SD) was 29.0 (4.6) kg/m2. Twenty-three per cent had both IFG and IGT, 63.9% had isolated IGT, and 13.3% had isolated IFG. Ethnic Asian Indian participants were more likely to report a family history of diabetes and had a higher waist circumference, compared with Chinese and Malay participants. Women were less likely than men to meet the physical activity recommendations (≥150 min of moderate-intensity physical activity per week), and dietary intake varied with both sex and ethnicity. Compared with other Asian diabetes prevention studies, the Pre-DICTED cohort had a higher mean age and BMI.

CONCLUSION

The Pre-DICTED cohort represents subjects at high risk of diabetes conversion. The study will evaluate the effectiveness of a community-based incentivized lifestyle intervention program in an urban Asian context.

A Smartphone App-Based Lifestyle Change Program for Prediabetes (D'LITE Study) in a Multiethnic Asian Population: A Randomized Controlled Trial

Introduction

Landmark studies have established that lifestyle interventions focused on weight loss, diet modification and physical activity can prevent diabetes progression. However, the effectiveness of mobile health application among Asians with prediabetes remains largely unexamined. We aimed to assess whether a smartphone app-based lifestyle intervention program would lead to weight loss, normoglycemia and improved metabolic indices in a multiethnic Asian population with prediabetes.

Research Design and Methods

This multicentre prediabetes RCT is part of the Diabetes Lifestyle Intervention using Technology Empowerment (D'LITE) trial. Adults (n = 148) with prediabetes and BMI ≥ 23 kg/m² were randomly allocated either to the intervention group (n = 72) empowered by self-monitoring features of the Nutritionist Buddy Diabetes app with in-app dietitian coaching for 6 months, or the control group (n = 76) receiving standard diet counseling at baseline. Primary outcome was defined as change in body weight at 6 months, while secondary outcomes included glycemic control and other metabolic indices analyzed using Generalized Linear Mixed Model analysis with intention-to-treat approach.

Results

Intervention group achieved a significantly greater weight loss of 4.2 vs. 1.3 kg [mean difference of −3.1 kg (95% CI −4.5 to −1.7), p < 0.001], and a 4.3-fold increased likelihood of achieving ≥ 5% weight loss, as compared to the control group at 6 months. The likelihood of achieving normoglycemia (defined as HbA_1c < 5.7%) was 2.1 times higher in intervention group than in the control group (p < 0.018). Changes to blood pressure, total and LDL cholesterol were not statistically significant.

Conclusion

An app-based lifestyle program led to clinically significant weight loss and improved glycemia, and can potentially augment current standard care in the prevention of diabetes among an Asian multiethnic population.

Clinical Trial Registration

anzctr.org.au, identifier: ACTRN12617001112358.

The Association between Trajectories of Anthropometric Variables and Risk of Diabetes among Prediabetic Chinese

In order to explore the association between trajectories of body mass index (BMI) and mid-upper arm circumference (MUAC) and diabetes and to assess the effectiveness of the models to predict diabetes among Chinese prediabetic people, we conducted this study. Using a national longitudinal study, 1529 cases were involved for analyzing the association between diabetes and BMI trajectories or MUAC trajectories. Growth mixture modeling was conducted among the prediabetic Chinese population to explore the trajectories of BMI and MUAC, and logistic regression was applied to evaluate the association between these trajectories and the risk of diabetes. The receiver operating characteristic curve (ROC) and the area under the curve (AUC) were applied to assess the feasibility of prediction. BMI and MUAC were categorized into 4-class trajectories, respectively. Statistically significant associations were observed between diabetes in certain BMI and MUAC trajectories. The AUC for trajectories of BMI and MUAC to predict diabetes was 0.752 (95% CI: 0.690-0.814). A simple cross-validation using logistic regression indicated an acceptable efficiency of the prediction. Diabetes prevention programs should emphasize the significance of body weight control and maintaining skeletal muscle mass and resistance training should be recommended for prediabetes.

Greater daily glucose variability and lower time in range assessed with continuous glucose monitoring are associated with greater aortic stiffness: The Maastricht Study

AIMS

CVD is the main cause of morbidity and mortality in individuals with diabetes. It is currently unclear whether daily glucose variability contributes to CVD. Therefore, we investigated whether glucose variability is associated with arterial measures that are considered important in CVD pathogenesis.

METHODS

We included participants of The Maastricht Study, an observational population-based cohort, who underwent at least 48 h of continuous glucose monitoring (CGM) (n = 853; age: 59.9 ± 8.6 years; 49% women, 23% type 2 diabetes). We studied the cross-sectional associations of two glucose variability indices (CGM-assessed SD [SD_CGM] and CGM-assessed CV [CV_CGM]) and time in range (TIR_CGM) with carotid-femoral pulse wave velocity (cf-PWV), carotid distensibility coefficient, carotid intima-media thickness, ankle-brachial index and circumferential wall stress via multiple linear regression.

RESULTS

Higher SD_CGM was associated with higher cf-PWV after adjusting for demographics, cardiovascular risk factors and lifestyle factors (regression coefficient [B] per 1 mmol/l SD_CGM [and corresponding 95% CI]: 0.413 m/s [0.147, 0.679], p = 0.002). In the model additionally adjusted for CGM-assessed mean sensor glucose (MSG_CGM), SD_CGM and MSG_CGM contributed similarly to cf-PWV (respective standardised regression coefficients [st.βs] and 95% CIs of 0.065 [-0.018, 0.167], p = 0.160; and 0.059 [-0.043, 0.164], p = 0.272). In the fully adjusted models, both higher CV_CGM (B [95% CI] per 10% CV_CGM: 0.303 m/s [0.046, 0.559], p = 0.021) and lower TIR_CGM (B [95% CI] per 10% TIR_CGM: -0.145 m/s [-0.252, -0.038] p = 0.008) were statistically significantly associated with higher cf-PWV. Such consistent associations were not observed for the other arterial measures.

CONCLUSIONS

Our findings show that greater daily glucose variability and lower TIR_CGM are associated with greater aortic stiffness (cf-PWV) but not with other arterial measures. If corroborated in prospective studies, these results support the development of therapeutic agents that target both daily glucose variability and TIR_CGM to prevent CVD.

Prevalence and Correlates of Social Stigma Toward Diabetes: Results From a Nationwide- Survey in Singapore

Aims: To examine the extent of social stigma toward diabetes among Singapore's multi-ethnic general population and determine whether this differs across socio-demographic sub-groups.

Methods: Data for this study came from a nationwide cross-sectional study. A diabetes stigma questionnaire comprising Social Distance Scale and Negative Attitudes and Stereotyping Scale was administered to those respondents who had not been diagnosed with diabetes. Exploratory factor analysis was conducted to determine the dimensionality of the instruments and validated using confirmatory factor analysis. Multiple linear regression analysis was conducted to examine associations between socio-demographic factors and measures of diabetes stigma.

Results: In all, 2,895 participants were recruited from the general population giving a response rate of 66.2%. Factor analyses found that a one-factor model resulted in an acceptable fit for both stigma scales, which measured social distance and negative attitudes and stereotyping, respectively. Multiple linear regression analyses identified Indian ethnicity (vs. Chinese), higher personal income (≥SGD2000 vs. < SGD 2000) and having close friends or family members who had been diagnosed with diabetes to be significantly associated with lower social distance scores while those aged 50–64 years and those with secondary and vocational education (vs. degree and above) were significantly associated with higher social distance scores. Those with a personal income of SG$2,000–3,999 and SGD $6,000 and above, and those with close friends or family members diagnosed with diabetes were significantly associated with lower negative attitudes and stereotyping scores. In contrast those aged 35 years and above, those with primary education and below, and those of Malay ethnicity were significantly associated with higher negative attitudes and stereotyping scores.

Conclusions: The study found a relatively low level of stigma toward diabetes in the general population of Singapore, although some stigmatizing beliefs emerged. While greater knowledge of diabetes could reduce stigma, anti-stigma messaging should be incorporated into the “War on Diabetes” programme in Singapore.

The heterogeneity of reversion to normoglycemia according to prediabetes type is not explained by lifestyle factors

Healthy lifestyle interventions and drug therapies are proven to have a positive preventative influence on normal glucose regulation in prediabetes. However, little is known on the specific role that these factors play on reversion to normal glycemia according to type of prediabetes. We used data from the Observational prospective cohort study, The Cohort study in Primary Health Care on the Evolution of Patients with Prediabetes from 2012 to 2015. A total of 1184 individuals aged 30-74 years old were included and classified based on the ADA in three mutually exclusive groups using either fasting plasma glucose (FPG) levels (from 100 to 125 mg/dl, FPG group), HbA_1c (5.7-6.4%, HbA1c group) or both impaired parameters. Information on lifestyle factors and biochemical parameters were collected at baseline. Reversion to normal glucose regulation was calculated at third year of follow-up. Relationship of lifestyle factor and type of prediabetes with reversion were estimated using odds ratios (ORs) with 95% confidence intervals (95% CIs) adjusting by different groups of confounders. Proportion of reversion rates were 31% for FPG group, 31% for HbA1c group and 7.9% for both altered parameters group, respectively. Optimal life style factors such as BMI < 25 kg/m²[OR (95% CI): 1.90 (1.20-3.01)], high adherence to Mediterranean diet 1.78 (1.21-2.63) and absence of abdominal obesity 1.70 (1.19-2.43) were the strongest predictors for reversion to normal glucose. However, those did not modify the ORs of reversion to normal glucose. Taking as reference those with both impaired parameters, subjects with FPG impairment (FPG group) had an OR of 4.87 (3.10-7.65) and 3.72 (2.39-5.78) for HbA1c group. These estimates remained almost the same after further adjustment for biochemical parameters and lifestyle factors (4.55(2.84-7.28) and 3.09 (1.92-4.97), respectively). Optimal lifestyle factors showed to be a positive predictor for reversion to normal glucose regulation however, the differences of reversion risk according type of prediabetes are not explained by lifestyle factors.

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.

Association of abdominal obesity with crossing capillaries in the finger nailfold in type 2 diabetes mellitus

Aim

Increased crossing of finger nailfold capillaries could be a novel visual marker of early microvascular damage among type 2 diabetes mellitus patients. Although abdominal obesity is an important driver of early microvascular damage, its association with an increase in the percentage of crossing capillaries remains uncertain. We investigated the association between abdominal obesity and an increase in the percentage of crossing capillaries in the finger nailfold in patients with type 2 diabetes mellitus.

Methods

This cross-sectional study enrolled 123 type 2 diabetes mellitus patients (age 40-75 years) who visited the outpatient diabetic clinic at Osaka University Hospital between May and October 2019. Abdominal obesity was defined as a waist circumference ≥ 90 cm in women and ≥ 85 cm in men. Capillary morphology was assessed by nailfold capillaroscopy based on the simple capillaroscopic definitions of the European League Against Rheumatism Study Group. The association between abdominal obesity and a high percentage of crossing capillaries in the finger nailfold (defined as the highest tertile of crossing capillaries) was analyzed using multivariable logistic regression.

Results

After adjusting for age, sex, smoking status, regular exercise, duration of diabetes, glycated hemoglobin, hypertension, and dyslipidemia, abdominal obesity was significantly associated with a high percentage of crossing capillaries (multivariable-adjusted odds ratios [95% confidence interval] = 2.70 [1.05-6.90], p = 0.038).

Conclusions

Abdominal obesity may play an important role in the increase in the percentage of crossing capillaries in the finger nailfold in patients with type 2 diabetes mellitus.

Microvascular Phenotyping in the Maastricht Study: Design and Main Findings, 2010-2018

Microvascular dysfunction (MVD) is a common pathophysiological change that occurs in various diseases, such as type 2 diabetes mellitus (T2DM), heart failure, dementia, and depression. Recent technical advances have enabled noninvasive measurement and quantification of microvascular changes in humans. In this paper, we describe the protocols of the microvascular measurements applied in the Maastricht Study, an ongoing prospective, population-based cohort study of persons aged 40–75 years being carried out in the southern part of the Netherlands (baseline data assessment, November 2010–January 2020). The study includes a variety of noninvasive measurements in skin, retina, brain, and sublingual tissue, as well as plasma and urine biomarker assessments. Following this, we summarize our main findings involving these microvascular measurements through the end of 2018. Finally, we provide a brief perspective on future microvascular investigations within the framework of the Maastricht Study.

Trajectories of body mass index and waist circumference before the onset of diabetes among people with prediabetes

BACKGROUND & AIMS

To investigate trajectories of body mass index (BMI) and waist circumference (WC) among prediabetic people who progressed to diabetes, people who remained with prediabetes, and those who returned to normoglycemia.

METHODS

We used data from 22,945 prediabetic people who received an annual health checkup for up to eight years. The development of diabetes was defined using the American Diabetes Association criteria. People who did not progress to diabetes during the observation period were classified as 'remained with prediabetes' or 'returned to normoglycemia', based on their last health checkup data. Trajectories of BMI and WC were evaluated using linear mixed models for repeated measures, with adjustment for a wide range of covariates.

RESULTS

During the study period, 2972 people progressed to diabetes, 4706 returned to normoglycemia, and 15,267 remained with prediabetes. People who progressed to diabetes had a larger increase in mean BMI from 7 years to 1 year prior to diagnosis, which was about three times that of people who remained with prediabetes (annual change rate, 0.20 [95% confidence interval; 0.15 to 0.24] vs 0.06 [0.04 to 0.08] kg/m² per year, P < 0.001), regardless of their BMI levels at the initial health checkup. Among people who returned to normoglycemia, mean BMI remained almost the same over time (-0.04 [-0.09 to 0.002] kg/m² per year), except for those with obesity (-0.16 [-0.28 to -0.05] kg/m² per year). As for WC, the annual change rate among people who developed diabetes was about 7 times that of people who remained with prediabetes (0.38 [0.32 to 0.45] vs 0.05 [0.03 to 0.08] cm per year, P < 0.001). We also observed a constant mean WC over time among people who had no central obesity and later returned to normoglycemia (-0.02 [-0.06 to 0.03] cm per year), and an annual decrease in mean WC among those who had central obesity and later returned to normoglycemia (-0.40 [-0.47 to -0.32] cm per year).

CONCLUSIONS

Our study provides strong evidence that avoiding weight gain could help prediabetic people minimize the risk of developing diabetes, regardless of whether they are obese. Losing weight could help obese people restore normoglycemia from a prediabetic state, whereas maintaining current weight may help nonobese people return to normoglycemia.

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.

Cumulative incidence and risk factors of prediabetes and type 2 diabetes in a Singaporean Malay cohort

AIMS

The aim of this work was to determine the cumulative incidence and independent risk factors of prediabetes and type 2 diabetes (T2DM) in a well-characterized cohort of Malays in Singapore.

METHODS

We included 1137 participants (mean age [SD]: 55 (10) years; 53.6% female) without diabetes (DM) at baseline from the Singapore Malay Eye Study, a population-based longitudinal study with baseline (2004-2006), and follow-up (2010-2013) examinations. Prediabetes was defined as an HbA1c between 5.7% and 6.4%, with no self-reported DM history or insulin/DM medication use. T2DM was defined as a random glucose level ≥200mg/dL or HbA1c>6.4% or use of insulin/DM medication. Age-standardized cumulative incidence was calculated as the crude 6-year cumulative incidence standardized to Singapore's Malay population census. Multivariable modified poisson regression models were utilized to determine the risk factors of incident prediabetes and T2DM.

RESULTS

The age-standardized 6-year cumulative incidence was 11.2% (95% CI 9.5, 13.1%) for T2DM, and 20.4% (95% CI 16.4, 25.2%) for prediabetes. Hypertension, higher body mass index (BMI) and higher Hba1c levels were associated with increased risk of T2DM, while older age and higher high density lipoprotein (HDL) cholesterol were protective (all P<0.05). Only higher BMI and HbA1c levels were independently associated with incident prediabetes (all P≤0.001).

CONCLUSIONS

While only one in ten adult Malays developed T2DM over 6-years, one in five developed prediabetes over the same time period. Our results suggest that evidence-based interventions addressing modifiable risk factors (obesity, prediabetes, hypertension, low HDL cholesterol) are needed to delay or prevent their onset.

Prediabetes and Type 2 Diabetes Are Associated With Generalized Microvascular Dysfunction

Background:

Type 2 diabetes (T2DM) is associated with an increased risk of cardiovascular disease. This can be partly explained by large-artery dysfunction, which already occurs in prediabetes (“ticking clock hypothesis”). Whether a similar phenomenon also applies to microvascular dysfunction is not known. We therefore tested the hypothesis that microvascular dysfunction is already present in prediabetes and is more severe in T2DM. To do so, we investigated the associations of prediabetes, T2DM, and measures of hyperglycemia with microvascular function measured as flicker light-induced retinal arteriolar dilation and heat-induced skin hyperemia.

Methods:

In the Maastricht Study, a T2DM-enriched population-based cohort study (n=2213, 51% men, aged [mean±standard deviation] 59.7±8.2 years), we determined flicker light-induced retinal arteriolar %-dilation (Dynamic Vessel Analyzer), heat-induced skin %-hyperemia (laser-Doppler flowmetry), and glucose metabolism status (oral glucose tolerance test; normal glucose metabolism [n=1269], prediabetes [n=335], or T2DM [n=609]). Differences were assessed with multivariable regression analyses adjusted for age, sex, body mass index, smoking, physical activity, systolic blood pressure, lipid profile, retinopathy, estimated glomerular filtration rate, (micro)albuminuria, the use of lipid-modifying and blood pressure-lowering medication, and prior cardiovascular disease.

Results:

Retinal arteriolar %-dilation was (mean±standard deviation) 3.4±2.8 in normal glucose metabolism, 3.0±2.7 in prediabetes, and 2.3±2.6 in T2DM. Adjusted analyses showed a lower arteriolar %-dilation in prediabetes (B=–0.20, 95% confidence interval –0.56 to 0.15) with further deterioration in T2DM (B=–0.61 [–0.97 to –0.25]) versus normal glucose metabolism ( P for trend=0.001). Skin %-hyperemia was (mean±standard deviation) 1235±810 in normal glucose metabolism, 1109±748 in prediabetes, and 937±683 in T2DM. Adjusted analyses showed a lower %-hyperemia in prediabetes (B=–46 [–163 to 72]) with further deterioration in T2DM (B=–184 [–297 to –71]) versus normal glucose metabolism ( P for trend=0.001). In addition, higher glycohemoglobin A1c and fasting plasma glucose were associated with lower retinal arteriolar %-dilation and skin %-hyperemia in fully adjusted models (for glycohemoglobin A1c, standardized B=–0.10 [–0.15 to –0.05], P <0.001 and standardized B=–0.13 [–0.19 to –0.07], P <0.001, respectively; for fasting plasma glucose, standardized B=–0.09 [–0.15 to –0.04], P <0.001 and standardized B=–0.10 [–0.15 to –0.04], P =0.002, respectively).

Conclusion:

Prediabetes, T2DM, and measures of hyperglycemia are independently associated with impaired microvascular function in the retina and skin. These findings support the concept that microvascular dysfunction precedes and thus may contribute to T2DM-associated cardiovascular disease and other complications, which may in part have a microvascular origin such as impaired cognition and heart failure.

Determinants of incident prediabetes and type 2 diabetes in a 7-year cohort in a developing country: The Isfahan Cohort Study

BACKGROUND

This study aimed to identify determinants of new onset type-2 diabetes (T2D) and prediabetes in a region with high rate of T2D but scarcity of evidence.

METHODS

Participants free of T2D were identified in a population-based study of adults older than 35 years living in the rural and urban areas of three districts in Iran in 2001 and were re-examined after 7 years. Biochemical measurements, anthropometric data, blood pressure, smoking status and dietary intake were determined at both measurement points through identical protocols and procedures. Data analysis was done using multivariate ordered logistic regressions.

RESULTS

Incidence rate of prediabetes and T2D was 32.3 (95%CI, 29.7-35.1) and 18.9 (17.1-20.9) per 1000 person-year, respectively. Odds of progression to prediabetes and T2D were increased with ageing, living in rural area (OR = 1.28), unhealthy diet (OR = 1.32), overweight (OR = 1.45), obesity (OR = 1.97), waist gain (OR = 1.37), high waist-to-hip ratio (OR = 1.35), hypertension (OR = 1.35), and hypertriglyceridemia (OR = 1.50); but reduced with higher education (OR = 0.76) and weight loss (OR = 0.67) in the adjusted models. In those with prediabetes at baseline, parental history of T2D (OR = 2.26), obesity (OR = 2.59), high waist circumference (OR = 2.03), and hypertriglyceridemia (OR = 1.94) were associated with developing T2D. No factor was found to be associated with regression from prediabetes to normoglycemia in adjusted models.

CONCLUSIONS

Current data endorses proposed statistical projections for the future trend of diabetes, and highlights the potential role of obesity specifically visceral type.

Early improvement predicts reduced risk of incident diabetes and improved cardiovascular risk in prediabetic Asian Indian men participating in a 2-year lifestyle intervention program

OBJECTIVE

Objectives of this ancillary analysis of a prospective, prevention study among Asian Indians with impaired glucose tolerance (IGT) were a) to quantify the reduction in incident diabetes at 24 months in participants who achieved normal glucose tolerance (NGT) at 6 months (NGT-6 m) compared with the other participants, b) the factors influencing the reversal to NGT at the end of the study at 24 months (NGT-24 m), and c) to assess changes in cardiometabolic risk factors in different categories of dysglycemia at 24 months.

RESEARCH DESIGN AND METHODS

Data from a 2-year primary prevention trial were used. Effect of reversion to NGT-6 m on incidence of type 2 diabetes mellitus (T2DM) was analyzed using the Cox proportional hazards model. Predictive variables for reversal to NGT were identified using multiple logistic regression analysis. Changes in cardiometabolic risk factors were estimated according to the final glycemic status using fixed-effect, mixed-linear regression modeling.

RESULTS

The risk of T2DM in 2 years was lower by 75% in NGT-6 m group (hazard ratio 0.25 [95% CI 0.12-0.52]). Predictive variables for reversal to NGT-24 m were good baseline β-cell function (odds ratio [OR] 2.79 [95% CI 2.30-3.40]) and its further improvement (OR 5.70 [95% CI 4.58-7.08]), and NGT-6 m (OR 2.10 [95% CI 1.14-3.83]). BMI decreased in those who reverted to NGT. Deterioration to T2DM was associated with an increase in the levels of cardiometabolic risk factors.

CONCLUSIONS

Early reversion to NGT by lifestyle intervention in prediabetic men was associated with a significant reduction in subsequent incidence of diabetes. Good baseline β-cell function and its further improvement and NGT-6 m were associated with reversion to NGT-24 months. Reversion to NGT was associated with modest improvements, whereas conversion to T2DM was associated with significant worsening of the cardiometabolic risk profile.

Impact of weight and weight change on normalization of prediabetes and on persistence of normal glucose tolerance in an older population: the KORA S4/F4 study

BACKGROUND AND AIMS

In a population-based cohort study with older subjects and without specific interventions, we investigated the impact of body mass index (BMI) and BMI change (as well as waist circumference and change of waist circumference) on reversion from prediabetes to normal glucose tolerance (NGT) and on long-term persistence of NGT.

MATERIALS AND METHODS

Oral glucose tolerance tests were conducted at baseline and at follow-up in a cohort study in Southern Germany (KORA S4/F4; 1223 subjects without diabetes aged 55-74 years at baseline in 1999-2001; 887 subjects (73%), of whom 436 had prediabetes at baseline, participated in the follow-up 7 years later).

RESULTS

BMI reduction, but not initial BMI, predicted reversion from prediabetes to NGT. The odds ratio (OR) for returning to NGT was 1.43 (95% CI: 1.18-1.73) for a BMI decrease of 1 kg m(-2), after adjustment for age, sex, baseline glucose values and lifestyle factors. Initial BMI had no effect on reversion to NGT (OR=0.98, 95% CI: 0.91-1.06, per kg m(-2)). Persistence of NGT was associated with baseline BMI (OR=0.94, 95% CI: 0.88-0.998) and BMI reduction (OR=1.16, 95% CI: 1.02-1.33, per decrease by 1 kg m(-2)). For waist circumference and change of waist circumference similar results were obtained.

CONCLUSION

In older adults, weight loss strongly increased the chances of returning from prediabetes to NGT irrespective of initial BMI. Long-term persistence of NGT depended both on initial BMI and on BMI change.

Adiponectin is Associated with Impaired Fasting Glucose in the Non-Diabetic Population

OBJECTIVES

Adiponectin is strongly associated with diabetes in the Western population. However, whether adiponectin is independently associated with impaired fasting glucose (IFG) in the non-obese population is unknown.

METHODS

The serum adiponectin, insulin resistance (IR), and waist circumference (WC) of 27,549 healthy Koreans were measured. Individuals were then classified into tertile groups by gender. IFG was defined as a fasting serum glucose of 100-125 mg/dL without diabetes. IR was calculated using the homeostasis model assessment of insulin resistance (HOMA-IR). The association of adiponectin and IFG was determined using logistic regression analysis.

RESULTS

WC and adiponectin were associated with IFG in both men and women. However, the association of WC with IFG was attenuated in both men and women after adjustment for the HOMA-IR. Adiponectin was still associated with IFG after adjustment for and stratification by HOMA-IR in men and women. Strong combined associations of IR and adiponectin with IFG were observed in men and women. Multivariate adjusted odds ratios (ORs) (95% confidence interval [CI]) among those in the highest tertile of IR and the lowest tertile of adiponectin were 9.8 (7.96 to 12.07) for men and 24.1 (13.86 to 41.94) for women.

CONCLUSION

These results suggest that adiponectin is strongly associated with IFG, and point to adiponectin as an additional diagnostic biomarker of IFG in the non-diabetic population.

Assessment and treatment of cardiovascular risk in prediabetes: impaired glucose tolerance and impaired fasting glucose

Individuals with impaired glucose tolerance (IGT) and/or impaired fasting glucose (IFG) are at high risk, not only to develop diabetes mellitus, but also to experience an adverse cardiovascular (CV) event (myocardial infarction, stroke, CV death) later in life. The underlying pathophysiologic disturbances (insulin resistance and impaired β-cell function) responsible for the development of type 2 diabetes are maximally/near maximally expressed in subjects with IGT/IFG. These individuals with so-called prediabetes manifest all of the same CV risk factors (dysglycemia, dyslipidemia, hypertension, obesity, physical inactivity, insulin resistance, procoagulant state, endothelial dysfunction, inflammation) that place patients with type 2 diabetes at high risk for macrovascular complications. The treatment of these CV risk factors should follow the same guidelines established for patients with type 2 diabetes, and should be aggressively followed to reduce future CV events.

Normalization of glucose intolerance in first-degree relatives of patients with type 2 diabetes

AIMS

The aim of this study was to estimate the conversion rate to normal glucose tolerance (NGT) from a state of abnormal glucose metabolism and to identify characteristics predicting the conversion rate in first-degree relatives (FDRs) of patients with type 2 diabetes with glucose intolerance.

METHODS

A total of 2368 (614 men and 1754 women) FDRs of consecutive patients with type 2 diabetes aged 20-70 years in 2003-2005 were followed through 2007. Glucose tolerance classification was based on the criteria of the American Diabetes Association base on standard 75 g 2-h oral glucose tolerance test. The study group consisted of 370 participants with glucose intolerance at baseline.

RESULTS

The conversion rates to normal glucose tolerance from impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) were 16.2% (95% confidence interval (CI) 13.30, 19.10) and 10.9% (95% CI: 5.7, 16.1) per year after an average of 2 years, respectively. Lower baseline fasting plasma glucose (HR 1.02, 95% CI: 1.01, 1.04) and 2-h (HR 1.02, 95% CI: 1.01, 1.04) glucose predicted conversion to NGT, as did changes in body mass index (BMI), waist circumference (WC), and lipids.

CONCLUSIONS

This is the first estimate of conversion rate and predictors from IFG and IGT to NGT in FDRs of people with type 2 diabetes in Iran. Lower baseline fasting, 2-h plasma glucose and changes in BMI, WC, and lipids predicted reversal to NGT at 24 months follow-up.

Factors determining normalization of glucose intolerance in middle-aged Swedish men and women: a 8-10-year follow-up

AIMS

To examine factors in middle-aged Swedish men and women predicting the conversion from a state of abnormal glucose regulation to normal glucose tolerance (NGT) after 8-10 years.

METHODS

At baseline 3128 men and 4821 women, aged 35-56 years, without previously diagnosed diabetes underwent an oral glucose tolerance test and completed a questionnaire. At follow-up, 2383 men and 3329 women were re-examined. The study group consisted of 156 men and 124 women with impaired fasting glucose (IFG), impaired glucose tolerance (IGT), or both at baseline.

RESULTS

The rate of reversal to NGT from IFG or IGT was similar regardless of gender. In participants having IFG or IGT, reversal to NGT was predicted by low fasting and 2-h insulin, homeostasis model assessment of insulin resistance and of pancreatic beta cell function, body mass index and waist circumference without differences between gender and baseline glucose tolerance group. Low 2-h glucose, however, predicted reversal to NGT in men with IFG at baseline, but not in men with IGT at baseline, or in women with either IFG or IGT at baseline. Men reverting to NGT had higher coffee consumption and women had higher baseline leisure-time physical activity. In multiple logistic regression, including all participants, low fasting and 2-h glucose remained independent predictors of reverting to NGT.

CONCLUSIONS

Factors predicting reversal to NGT were measures correlated with low insulin resistance, but also lower insulin secretion, perhaps indicating a lower pancreatic beta cell workload in those who reverted. In men, but not in women, low 2-h glucose was of predictive value.

Addition of metformin to a lifestyle modification program in adolescents with insulin resistance

OBJECTIVE

To evaluate whether metformin, when added to a program of personal goal setting, improves weight loss and clinical status in obese adolescents.

STUDY DESIGN

In a randomized double-blind placebo controlled trial, 85 adolescents with insulin resistance were randomized to receive metformin (70%) or placebo (30%), along with monthly goal setting for diet and exercise modification. Anthropometric measures, fasting blood analysis, and glucose tolerance tests were performed at baseline and 6 months.

RESULTS

Mean age was 15.7 years. Mean body mass index (BMI) was 39.7 kg/m(2). 71% were female, 58% were Hispanic, and 34% were African-American. 76% of participants completed the study. Goal setting alone did not result in significant weight loss. In addition, there were no group differences between metformin and placebo in weight loss or measures of glucose metabolism. However, among females taking metformin, there was a significant decrease in BMI not seen in the placebo group. Furthermore, metformin adherence, when accompanied by lifestyle change, was a predictor of BMI decrease of 5% or more. 60% of 10 subjects who adhered to metformin and decreased portion size decreased BMI by >5%.

CONCLUSIONS

In this group of predominately minority adolescents, monthly goal setting alone did not lead to weight loss. Although the addition of metformin had no effect on weight loss overall, the agent did significantly increase weight loss among females and weight loss was predicted by degree of metformin adherence. However, weight loss was only found in those participants also reporting lifestyle change, particularly a decrease in portion sizes. These results suggest that metformin may be a useful agent to promote short-term weight loss among girls making modest lifestyle changes.

Glucose metabolism disorder in obese children assessed by continuous glucose monitoring system

BACKGROUND

Continuous glucose monitoring system (CGMS) can measure glucose levels at 5-minute intervals over a few days, and may be used to detect hypoglycemia, guide insulin therapy, and control glucose levels. This study was undertaken to assess the glucose metabolism disorder by CGMS in obese children.

METHODS

Eighty-four obese children were studied. Interstitial fluid (ISF) glucose levels were measured by CGMS for 24 hours covering the time for oral glucose tolerance test (OGTT). Impaired glucose tolerance (IGT), impaired fasting glucose (IFG), type 2 diabetic mellitus (T2DM) and hypoglycemia were assessed by CGMS.

RESULTS

Five children failed to complete CGMS test. The glucose levels in ISF measured by CGMS were highly correlated with those in capillary samples (r=0.775, P<0.001). However, the correlation between ISF and capillary glucose levels was lower during the first hour than that in the later time period (r=0.722 vs r=0.830), and the ISF glucose levels in 69.62% of children were higher than baseline levels in the initial 1-3 hours. In 79 obese children who finished the CGMS, 2 children had IFG, 2 had IGT, 3 had IFG + IGT, and 2 had T2DM. Nocturnal hypoglycemia was noted during the overnight fasting in 11 children (13.92%).

CONCLUSIONS

Our data suggest that glucose metabolism disorder including hyperglycemia and hypoglycemia is very common in obese children. Further studies are required to improve the precision of the CGMS in children.

Annual incidence and relative risk of diabetes in people with various categories of dysglycemia: a systematic overview and meta-analysis of prospective studies

BACKGROUND

Several estimates of the risk of progression to diabetes in people with impaired fasting glucose (IFG) or impaired glucose tolerance (IGT) have been reported.

OBJECTIVE

To provide an estimate of the risk of progression to diabetes and regression to normoglycemia in these populations.

DESIGN

Systematic overview and meta-analysis of prospective cohort studies published from 1979 until 2004.

SETTING

Global cohort studies.

PATIENTS

People with IFG or IGT detected by a screening oral glucose tolerance test.

MEASUREMENTS

Fasting and post-load plasma glucose levels.

RESULTS

The absolute annual incidence of diabetes in individuals with various categories of IFG or IGT varied from 5 to 10%. Compared to normoglycemic people the meta-analyzed relative risk and 95% confidence interval for diabetes was: 6.35 (4.87-7.82) in people with IGT; 5.52 (3.13-7.91) in people with isolated IGT; 4.66 (2.47-6.85) in people with IFG; 7.54 (4.63-10.45) in people with isolated IFG; and 12.13 (4.27-20.00) in people with both IFG and IGT. People with IGT were 0.33 times as likely to be normoglycemic after 1 year compared to people with normal glucose tolerance (95% CI 0.23-0.43).

LIMITATIONS

Studies that used differing criteria for IFG and IGT were included, and participants were classified on the basis of only one test.

CONCLUSION

IFG and IGT are associated with similar, high relative risk for incident diabetes. The combined abnormality of IFG plus IGT is associated with the highest relative risk.

Predicting the 20-year diabetes incidence rate

BACKGROUND

The long-range prediction from clinical variables of the onset of diabetes is important to patients and clinicians. Our objective was to evaluate the efficacy of various glucose-related clinical measurements in predicting the 20-year risk of developing type 2 diabetes (T2DM) in an elderly population.

METHODS

In a prospective study, 672 men and women aged 59-92 years, who were not diabetic in 1980 and were part of a nationwide longitudinal randomized study, were followed-up in 2000-2003. Fasting glucose, 1- and 2-h post-oral glucose tolerance and insulin were measured in 1980 and 2000-2003.

RESULTS

A group of 174 (25.9%) survivors had progressed to diabetes during the 20-year follow-up. Fasting glucose values were a good predictor for diabetes. With the 100 mg/dL cut-off of impaired fasting glucose (IFG), a 2-4-times higher predictive sensitivity followed the dramatic increase in IFG prevalence compared to the 110 mg/dL cut-off, but at a cost of reduced specificity and positive predictive value (PPV). By receiver operating curve (ROC) analysis, a 1-h post-load glucose was similar to 2 h and fasting glucose in prediction of the 20-year incidence of diabetes, and classifying correctly the 77, 74 and 73% of the group, respectively. In adjusted logistic regressions, 2.28, 1.78 and 1.69-folds increased the 20-year risk, and were associated with each SD increment of the respective glucose values (p < 0.001).

CONCLUSIONS

Although the best population-based strategy for the diagnosis of T2DM would be the combination of fasting glucose followed by post-load glucose, for the purposes of long-term prediction of T2DM risk, fasting glucose is sufficient.

Lowering the criterion for impaired fasting glucose: impact on disease prevalence and associated risk of diabetes and ischemic heart disease

OBJECTIVE

To determine the effect of lowering the fasting plasma glucose (FPG) criterion for impaired fasting glucose (IFG) on the prevalence of IFG, the risks of diabetes, and cardiovascular disease (CVD) associated with IFG.

RESEARCH DESIGN AND METHODS

Three studies were used: 1). the 1998 National Health Survey (NHS98), a randomly selected cross-sectional sample of 4723 subjects; 2). the Singapore Impaired Glucose Tolerance (IGT) Follow-up Study, a cohort study comprising 295 IGT and 292 normal glucose tolerance subjects (frequency matched for age, sex, and ethnic group) followed up from 1992 to 2000; and 3). the Singapore CVD Cohort Study, comprising 5920 subjects from three cross-sectional studies in whom the first ischemic heart disease (IHD) event was identified through linkage to registry databases. Risk of diabetes (Singapore IGT Follow-up study) was estimated using logistic regression adjusted for age, sex, and ethnicity. Risk of IHD (Singapore CVD cohort) was estimated using stratified (by study, from which data were derived) Cox's proportional hazards models adjusted for age, sex, and ethnicity.

RESULTS

Lowering the criterion for diagnosing IFG to 5.6 mmol/l increased the prevalence of IFG from 9.5 to 32.3% in the NHS98. The lower cutoff identified more subjects at risk of diabetes and IHD, but the relative risk was lower than that for IGT.

CONCLUSIONS

Greater efforts to identify those with IGT, or a group at similar risk of diabetes and CVD, may be a more efficient public health measure than lowering the FPG criterion for diagnosing IFG.