Breaking the Chain: The Crucial Role of Prediabetes Screening in Preventing Diabetes and Its Complications
Preventing Diabetes -A Stitch in Time Saves Nine:
Diabetes prevention has become extremely critical, necessitating all healthcare stakeholders’ actions. Many diabetes-preventative interventions continue to focus primarily on prediabetes. Data regarding prediabetes prevalence is useful in evaluating and predicting the present and potential future diabetes pandemics(1).
Prediabetes: Indian Scenario
The Indian Council of Medical Research–India Diabetes (ICMR-INDIAB) study emphasises the enormous burden of prediabetes, where the prevalence of prediabetes in India is estimated to be 136 million, higher than the prevalence of diabetes [101 million] (1).
Prediabetes Conversion to Diabetes: The conversion rate from prediabetes to type 2 diabetes (T2D) is very high among Asian Indians (2). Mohan et al. reported more than 40% of Indian prediabetes patients developed T2DM within 8 years of follow-up(3). A recently published paper by K.M. Venkat Narayan et al indicated that among the Indian population, the annual transition probability from isolated impaired fasting glucose (i-IFG) to diabetes is 8.6%, while that from impaired glucose tolerance (IGT) to diabetes is 13.9%. The average time spent by Indians in IFG (impaired fasting glucose) and IGT are 9.7 and 6.1 years, respectively (4).
Prediabetes and Complications: A study from India found that over 10% of people with prediabetes had vascular complications linked to diabetes, indicating that prediabetes is linked to an increased risk of vascular complications. Prediabetes also increases cardiovascular disease [incidence rate per 10,000 person-years: 58.3 for those with normal glucose regulation vs. 67.0 for those with prediabetes] and all-cause mortality [incidence rate per 10,000 person-years: 73.6 for those with normal glucose regulation vs. 81 for those with prediabetes] (5).
Why is Prediabetes Screening Crucial? High insulin resistance is prominent in Asian Indians, which hastens the progression of diabetes (5). The average time spent by Indians with isolated impaired fasting glucose (i-IFG) and IGT is 9.7 and 6.1 years, respectively (4). Early screening, detection, and treatment of prediabetes are essential in the Indian population since they lower the risk of developing diabetes and its complications (2).
Prediabetes Screening & Tools
The RSSDI(Research Society for Study of Diabetes in India) recommends screening of prediabetes in individuals presenting to health care settings for unrelated illnesses, family members of diabetes patients, antenatal care, dental care, overweight children and adolescents at the onset of puberty, and community screening wherever feasible (6). The RSSDI guideline and ADA (American Diabetes Association) 2024 diagnosed prediabetes in an individual having an A1C 5.7–6.4% (39–47 mmol/mol), IFG 100 mg/dL (5.6 mmol/L) to 125 mg/dL (6.9 mmol/L) and 2-h PG during 75-g OGTT (oral glucose tolerance test) 140 mg/dL (7.8 mmol/L) to 199 mg/dL [11.0 mmol/L] (6,7).
Non-invasive, easy-to-apply ancillary screening tools are needed for identifying and screening individuals with prediabetes (8). Mohan et al. developed a simple screening tool, the Indian Diabetes Risk Score (IDRS), to screen the population for diabetes. IDRS is computed using age, family history of diabetes, waist circumference, and a subject’s physical activity level. The score ranges from 0 to 100; a score ≥60 denotes high risk, 30–60 denotes moderate, and a score <30 in a subject denotes low risk of developing diabetes in the future (9). More recently, the International Diabetes Federation (IDF) has suggested the use of 1-h post-load plasma glucose ≥ 155 mg/dL (8.6 mmol/L) in people with normal glucose tolerance (NGT) during an OGTT to indicate prediabetes (10).
Risk Factors for the Development of Prediabetes
According to Indian Expert Group Consensus, the common risk factors for prediabetes in India include age (45 or older), positive family history of diabetes and gestational diabetes, high HbA1c, physical inactivity, poor high-density lipoprotein cholesterol (HDL-C) below 35 mg/dL, high triglycerides (TG) above 200 mg/dL, hypertension or being on hypertension medications (2).
Early Prediabetes Screening Helps in Early Identification & Management
A meta-analysis of 7 interventional studies involving 26,389 patients assessed the benefits of effective interventions, which included lifestyle (including dietary and exercise recommendations) or drugs (including acarbose and metformin) on microvascular and macrovascular events in prediabetic patients. The results provided that early effective intervention significantly reduced all-cause mortality by 18% in prediabetic patients without a history of cardiovascular disease (95% CI=0.69~0.98, P=0.03) and retinopathy by 38% [95% CI 0.70-0.98] (11). Another cross-sectional study (n=2968) assessed the prevalence of prediabetes and undiagnosed diabetes in patients with cardiovascular disease according to the ADA criteria. The results showed about 32.4% of them had prediabetes, and up to one-third of those with undiagnosed prediabetes had already been diagnosed with cardiovascular complications (12). These suggest that an early diagnosis and interventions can benefit prediabetes patients.
A lifestyle change may reduce the number of prediabetic people who develop diabetes to 20% (13). The Indian Diabetes Prevention Program (IDPP) trial also noted this benefit in Asian Indians. A moderate-intensity exercise, just 150 minutes per week of brisk walking, enhanced insulin sensitivity among prediabetes. However, lifestyle interventions may not be effective and sufficient in all cases of prediabetes. Metformin is the only pharmacologic agent recommended for preventing or postponing T2D. The DCGI (Drug Controller General of India) approved the use of metformin in prediabetes, where lifestyle intervention is insufficiently effective in reducing body weight and improving glucose tolerance (2).
Take Home Messages
- Prediabetes needs to be the primary target for diabetes prevention. Indian population spends significant years in isolated impaired fasting glucose (i-IFG) and impaired glucose tolerance (IGT).
- Early screening, detection, and treatment of prediabetes lowers the risk of developing diabetes and its complications.
- Indian Diabetes Risk Score and 1-h post-load plasma glucose ≥ 155 mg/dL are simple, practical inexpensive screening tools suggested for the Indian population.
- Early interventions reduced cardiovascular disease by 18% and retinopathy by 38% in prediabetes.
- Lifestyle changes could delay the onset of diabetes, and Metformin is suggested where lifestyle changes are insufficient. Metformin is DCGI approved treatment for the management of prediabetes.
References:
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