A Reappraisal of Prediabetes

Prediabetes and Cardiometabolic Risk: The Need for Improved Diagnostic Strategies and Treatment to Prevent Diabetes and Cardiovascular Disease

The progression from prediabetes to type-2 diabetes depends on multiple pathophysiological, clinical, and epidemiological factors that generally overlap. Both insulin resistance and decreased insulin secretion are considered to be the main causes. The diagnosis and approach to the prediabetic patient are heterogeneous. There is no agreement on the diagnostic criteria to identify prediabetic subjects or the approach to those with insufficient responses to treatment, with respect to regression to normal glycemic values or the prevention of complications. The stratification of prediabetic patients, considering the indicators of impaired fasting glucose, impaired glucose tolerance, or HbA1c, can help to identify the sub-phenotypes of subjects at risk for T2DM. However, considering other associated risk factors, such as impaired lipid profiles, or risk scores, such as the Finnish Diabetes Risk Score, may improve classification. Nevertheless, we still do not have enough information regarding cardiovascular risk reduction. The sub-phenotyping of subjects with prediabetes may provide an opportunity to improve the screening and management of cardiometabolic risk in subjects with prediabetes.

Prevalence of pre-diabetes in adults aged 25 - 45 years in a Durban-based clinical setting, South Africa: A retrospective study

AIM

Due to pre-diabetes being underexplored, its prevalence was investigated in study participants aged 25-45 years in a Durban-based tertiary-level clinical setting in South Africa.

METHODS

The study was done using a retrospective study design. Fasting blood samples from consented patients with no previous diagnosis of diabetes and within the specified age range were collected from King Edward Hospital in Durban. The pre-diabetes diagnosis was confirmed in participants with fasting glucose concentrations between 5.6 and 6.9 mmol/L and glycated haemoglobin (HbA1c) levels between 5.7 % and 6.4 % using the American Diabetes Association (ADA) and World Health Organisation (WHO) diagnosis criteria. The study participants' characterisation was stratified according to the diagnosis criterion, age, gender and ethnicity.

RESULTS

An alarming 68 % average pre-diabetes prevalence across ADA and WHO criteria in the Durban, eThekwini district sample population. The highest prevalence was recorded using the IFG criterion (83%) and the lowest when using the HbA1c criterion (54 %). Between the White, Black and Indian ethnic groups, the Indian group were more predisposed to pre-diabetes onset, with a prevalence of 62.7 %.

CONCLUSION

If pre-diabetes management is unattended, an unprecedented increase in metabolic disorders such as Type 2 Diabetes Mellitus (T2DM) and all-cause mortality incidence can be expected. Therefore, the study reveals a window of opportunity to intensify preventative measures and mitigate the incidence of T2DM.

Metabolic non-communicable disease health report of India: the ICMR-INDIAB national cross-sectional study (ICMR-INDIAB-17)

BACKGROUND

Non-communicable disease (NCD) rates are rapidly increasing in India with wide regional variations. We aimed to quantify the prevalence of metabolic NCDs in India and analyse interstate and inter-regional variations.

METHODS

The Indian Council of Medical Research-India Diabetes (ICMR-INDIAB) study, a cross-sectional population-based survey, assessed a representative sample of individuals aged 20 years and older drawn from urban and rural areas of 31 states, union territories, and the National Capital Territory of India. We conducted the survey in multiple phases with a stratified multistage sampling design, using three-level stratification based on geography, population size, and socioeconomic status of each state. Diabetes and prediabetes were diagnosed using the WHO criteria, hypertension using the Eighth Joint National Committee guidelines, obesity (generalised and abdominal) using the WHO Asia Pacific guidelines, and dyslipidaemia using the National Cholesterol Education Program-Adult Treatment Panel III guidelines.

FINDINGS

A total of 113 043 individuals (79 506 from rural areas and 33 537 from urban areas) participated in the ICMR-INDIAB study between Oct 18, 2008 and Dec 17, 2020. The overall weighted prevalence of diabetes was 11·4% (95% CI 10·2-12·5; 10 151 of 107 119 individuals), prediabetes 15·3% (13·9-16·6; 15 496 of 107 119 individuals), hypertension 35·5% (33·8-37·3; 35 172 of 111 439 individuals), generalised obesity 28·6% (26·9-30·3; 29 861 of 110 368 individuals), abdominal obesity 39·5% (37·7-41·4; 40 121 of 108 665 individuals), and dyslipidaemia 81·2% (77·9-84·5; 14 895 of 18 492 of 25 647). All metabolic NCDs except prediabetes were more frequent in urban than rural areas. In many states with a lower human development index, the ratio of diabetes to prediabetes was less than 1.

INTERPRETATION

The prevalence of diabetes and other metabolic NCDs in India is considerably higher than previously estimated. While the diabetes epidemic is stabilising in the more developed states of the country, it is still increasing in most other states. Thus, there are serious implications for the nation, warranting urgent state-specific policies and interventions to arrest the rapidly rising epidemic of metabolic NCDs in India.

FUNDING

Indian Council of Medical Research and Department of Health Research, Ministry of Health and Family Welfare, Government of India.

Cardiovascular risk, fatty liver disease, glucose and insulin curve among prediabetes phenotypes in Peruvian population

Aims

To describe the cardiovascular risks, fatty liver disease, and glucose and insulin curve among prediabetes phenotypes (PPh) in Peruvian population.

Methods

A study was carried out using a secondary database of a series of patients with identified risk factors for diabetes mellitus type 2 in one clinic in Lima, Peru. Patients were divided according with the OGTT in impaired glucose 2h or IGT(Pph1), impaired fasting glucose or IFG(Pph3) or both(Pph2).

Results

259 patients were identified for analysis, 149 of whom had normal OGTT, 94 had prediabetes (36.3%), and 16 diabetes (6.2%). We found that 37(39.4%), 37(39.4%) and 20(21.2%) presented Pph1, Pph-2 and Pph-3 respectively. Most of the cardiovascular risks and hepatic function comparison showed no difference in our study sample groups. However, we found that Pph2 showed significantly higher abnormalities in HDL-c, triglycerides, hepatic steatosis, and HOMA-IR compared with normal OGTT group (p < 0.05). Interestingly, this difference was not seen with the other phenotypes. Also, hepatic steatosis was higher in Pph2 compared to Pph3 (p < 0.05). HOMA-IR was high in Phenotype 2 compared with Phenotype 1. Regarding hepatic steatosis, this was high in all prediabetes phenotypes, however we found this to be of statistical significance in Pph2 compared to Pph3 (p < 0.01).

Conclusions

In general, prediabetes phenotypes show a similar association with cardiovascular risk factors and hepatic steatosis, however, Pph2 show more differences in specific comparisons. We believe that this study is a starting point for further investigation to understand prediabetes in Peruvian population and be able to improve disease risk stratification.

Historical review of the diagnosis of prediabetes/intermediate hyperglycemia: Case for the international criteria

In 1997, the ADA recommended an IFG criterion for diagnosing prediabetes/intermediate hyperglycemia of FPG concentrations of 6.1-6.9 mmol/L (110-125 mg/dL). In 2003, they lowered it to 5.6-6.9 mmol/L (100-125 mg/dL) to equalize developing diabetes between IGT and IFG. International organizations accepted the first IFG criterion but not the second. The ADA subsequently recommended HbA1c levels for diagnosing prediabetes/intermediate hyperglycemia of 39-47 mmol/mol (5.7-6.4%) based on a model that utilized the composite risk of developing diabetes and CVD. However, the evidence that the intermediate hyperglycemia that defines prediabetes is independently associated with CVD is weak. Rather, the other risk factors for CVD in the metabolic syndrome are responsible. The WHO opined that prediabetes/intermediate hyperglycemia could not be diagnosed by HbA1c levels but the Canadians and Europeans recommended its diagnosis by values of 42-47 mmol/mol (6.0-6.4%). With the ADA criteria, approximately one-half of people are normal on re-testing, one-third spontaneously revert to normal over time and two-thirds never develop diabetes in their lifetimes. The international criteria for prediabetes/intermediate hyperglycemia increase the risk of developing diabetes and might motivate these individuals to more seriously undertake lifestyle interventions as a preventive measure.

Association of Mixed Use of Electronic and Conventional Cigarettes and Exposure to Secondhand Smoke With Prediabetes

CONTEXT

Despite previous studies regarding the association between smoking and diabetes, the effects of electronic cigarettes and secondhand smoke (SHS) on glucose metabolism and insulin sensitivity have not been fully elucidated.

OBJECTIVE

To examine the association of mixed electronic and conventional cigarette use and exposure to SHS with prediabetes.

DESIGN

Data from the 2014-2018 Korean National Health and Nutrition Examination Survey were analyzed.

SETTING

Nationwide population-based.

PARTICIPANTS

Of 39 199 participants, 22 385 participants (9490 men, 12 895 women) without diabetes were included. The main independent variables were smoking behaviors, including exposure to SHS.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Prediabetes (hemoglobin A1C of 5.7-6.4%).

RESULTS

Of 22 385 participants without diabetes, 6735 had prediabetes. Mixed cigarette use was associated with a 1.57-fold increase in the odds of prediabetes when compared with never-smoking [odds ratio (OR) = 1.57, 95% CI = 1.29-1.92] and a 1.27-fold increase when compared with conventional cigarette use only (OR = 1.27, 95% CI = 1.07-1.52). Participants who were current nonsmokers, but mixed users in the past had an increased risk of prediabetes (OR = 1.54, 95% CI = 1.04-2.13). There was no significant association between prediabetes and current nonsmoking in individuals with previous conventional cigarette use only. Among never-smokers, exposure to SHS significantly increased the risk of prediabetes (OR = 1.16, 95% CI = 1.04-1.30).

CONCLUSIONS

Mixed use of electronic and conventional cigarettes and exposure to SHS increased the risk of prediabetes. Further studies are required to comprehensively investigate the molecular biology underlying the effects of previous and current mixed use of electronic cigarettes and SHS on glucose metabolism.

Utility of polygenic embryo screening for disease depends on the selection strategy

Polygenic risk scores (PRSs) have been offered since 2019 to screen in vitro fertilization embryos for genetic liability to adult diseases, despite a lack of comprehensive modeling of expected outcomes. Here we predict, based on the liability threshold model, the expected reduction in complex disease risk following polygenic embryo screening for a single disease. A strong determinant of the potential utility of such screening is the selection strategy, a factor that has not been previously studied. When only embryos with a very high PRS are excluded, the achieved risk reduction is minimal. In contrast, selecting the embryo with the lowest PRS can lead to substantial relative risk reductions, given a sufficient number of viable embryos. We systematically examine the impact of several factors on the utility of screening, including: variance explained by the PRS, number of embryos, disease prevalence, parental PRSs, and parental disease status. We consider both relative and absolute risk reductions, as well as population-averaged and per-couple risk reductions, and also examine the risk of pleiotropic effects. Finally, we confirm our theoretical predictions by simulating 'virtual' couples and offspring based on real genomes from schizophrenia and Crohn's disease case-control studies. We discuss the assumptions and limitations of our model, as well as the potential emerging ethical concerns.

Metformin Should Not Be Used to Treat Prediabetes

Based on the results of the Diabetes Prevention Program Outcomes Study (DPPOS), in which metformin significantly decreased the development of diabetes in individuals with baseline fasting plasma glucose (FPG) concentrations of 110-125 vs. 100-109 mg/dL (6.1-6.9 vs. 5.6-6.0 mmol/L) and A1C levels 6.0-6.4% (42-46 mmol/mol) vs. <6.0% and in women with a history of gestational diabetes mellitus, it has been suggested that metformin should be used to treat people with prediabetes. Since the association between prediabetes and cardiovascular disease is due to the associated nonglycemic risk factors in people with prediabetes, not to the slightly increased glycemia, the only reason to treat with metformin is to delay or prevent the development of diabetes. There are three reasons not to do so. First, approximately two-thirds of people with prediabetes do not develop diabetes, even after many years. Second, approximately one-third of people with prediabetes return to normal glucose regulation. Third, people who meet the glycemic criteria for prediabetes are not at risk for the microvascular complications of diabetes and thus metformin treatment will not affect this important outcome. Why put people who are not at risk for the microvascular complications of diabetes on a drug (possibly for the rest of their lives) that has no immediate advantage except to lower subdiabetes glycemia to even lower levels? Rather, individuals at the highest risk for developing diabetes-i.e., those with FPG concentrations of 110-125 mg/dL (6.1-6.9 mmol/L) or A1C levels of 6.0-6.4% (42-46 mmol/mol) or women with a history of gestational diabetes mellitus-should be followed closely and metformin immediately introduced only when they are diagnosed with diabetes.

Lessons from Launching the Diabetes Prevention Program in a Large Integrated Health Care Delivery System: A Case Study

There is urgent need for health systems to prevent diabetes. To date, few health systems have implemented the evidence-based Diabetes Prevention Program (DPP), and the few that have mostly partnered with community-based organizations to implement the program. Given the recent decision by the Centers for Medicare & Medicaid Services to reimburse for diabetes prevention, there is likely much interest in how such programs can be implemented within large health systems or how community partnerships can be expanded to support DPP implementation. Beginning in 2010, Montefiore Health System (MHS), a large health care system in the Bronx, NY, partnered with the Young Men's Christian Association (YMCA) of Greater New York to deliver the YMCA's DPP. Over 4 years, 1390 referrals to YMCA's DPP were made; 287 participants attended ≥3 classes, and average weight loss was 3.4%. Because of increased patient demand and internal capacity, MHS assumed responsibility for DPP implementation in May 2015. Fully integrating the program within the health system took 5–6 months, including configuring electronic health record templates/reports, hiring a coordinator, and creating clinical referral workflows/training guides. Billing workflows were designed for risk-based contracts. In the first 11 months of implementation, 1277 referrals were made, and referrals increased over time. Twenty-four class cycles were initiated, and 282 patients began attending classes. Average weight loss among 61 graduates from the Summer/Fall 2015 wave of MDPP classes was 3.8%. Additional opportunities for expansion include training allied health staff, providing patient incentives, increasing master trainer capacity, offering DPP to employees, and securing reimbursement.