Undiagnosed Diabetes in Acute Coronary Syndrome: A Silent Threat in Pakistan

Diabetes mellitus (DM) has emerged as one of the most pressing public health challenges globally, and Pakistan stands among the countries most severely affected. With rising urbanization, sedentary lifestyles, and dietary transitions, the burden of diabetes continues to escalate. Of particular concern is the substantial proportion of individuals living with undiagnosed diabetes mellitus (UDM), which often remains clinically silent until it manifests through acute complications such as acute coronary syndrome (ACS). In Pakistan, where healthcare access and screening practices remain inconsistent, UDM represents a critical yet under-recognized contributor to cardiovascular morbidity and mortality [1]. The epidemiological landscape in Pakistan highlights the magnitude of the problem. Large-scale national data from the second National Diabetes Survey of Pakistan (NDSP 2016–2017) reported that a significant proportion of individuals with diabetes remain undiagnosed, with an estimated prevalence of around 7.1% in the general population [1]. Meanwhile, overall diabetes prevalence has reached nearly 17% when assessed using HbA1c-based criteria [2]. These findings underscore a dual burden: a high prevalence of diabetes alongside a substantial hidden population of undiagnosed cases. This hidden burden becomes particularly dangerous in the setting of ACS. Cardiovascular disease is already the leading cause of mortality in Pakistan, and diabetes is a well-established risk factor that accelerates atherosclerosis, promotes endothelial dysfunction, and increases thrombogenicity. Importantly, patients with undiagnosed diabetes often present with ACS without prior risk stratification or glycemic control, resulting in worse clinical outcomes. Studies from Pakistan have consistently demonstrated that a notable proportion of ACS patients have previously unrecognized diabetes. For example, a study from Lahore reported UDM in approximately 7.1% of ACS patients [3], while more recent data have suggested substantially higher rates, reaching up to 38.8% depending on diagnostic criteria and study population [4]. The variability in reported prevalence reflects differences in methodology, particularly the use of diagnostic tools such as fasting glucose, oral glucose tolerance testing (OGTT), and glycated hemoglobin (HbA1c). Among these, HbA1c has gained increasing importance as it reflects chronic glycemic exposure over the preceding two to three months and is less influenced by acute stress hyperglycemia. This is especially relevant in ACS, where transient hyperglycemia can occur as part of the stress response. Pakistani data have also emphasized the utility of HbA1c in identifying undiagnosed diabetes and refining diagnostic thresholds tailored to the local population [5]. From a clinical perspective, the presence of UDM in ACS patients has profound implications. Undiagnosed diabetes is associated with more extensive coronary artery disease, delayed presentation due to atypical symptoms, and a higher likelihood of complications such as heart failure and arrhythmias. Hyperglycemia exacerbates myocardial injury through multiple mechanisms, including oxidative stress, inflammation, and impaired microvascular perfusion. Consequently, patients with UDM often experience worse short-term and long-term outcomes compared to their non-diabetic counterparts [6]. In the Pakistani healthcare context, several systemic challenges contribute to the high burden of UDM. First, there is a lack of routine screening at the primary care level. Many individuals remain unaware of their glycemic status until they present with complications. Second, socioeconomic disparities limit access to diagnostic facilities, particularly in rural areas. Third, public awareness regarding diabetes risk factors and early symptoms remains inadequate. Cultural factors, including dietary habits and low physical activity levels, further compound the problem [7]. Another critical issue is the fragmentation of care. Patients presenting with ACS are often managed primarily for their acute cardiac condition, while underlying metabolic disorders such as diabetes may not receive adequate attention. This represents a missed opportunity for early diagnosis and intervention. Incorporating routine HbA1c testing in all ACS admissions could serve as a simple and cost-effective strategy to identify previously undiagnosed diabetes. Such an approach has the potential to improve risk stratification and guide both acute and long-term management [8]. From a policy perspective, addressing UDM requires a multi-pronged strategy. At the population level, there is a need for nationwide screening programs targeting high-risk groups, including individuals with obesity, family history of diabetes, and hypertension. Community-based interventions focusing on lifestyle modification, dietary education, and physical activity promotion are essential. At the healthcare system level, strengthening primary care infrastructure and integrating diabetes screening into routine clinical practice can help bridge the diagnostic gap [1-8]. Furthermore, clinical guidelines in Pakistan should emphasize the importance of screening for dysglycemia in all patients presenting with ACS. This includes not only measuring random or fasting glucose but also incorporating HbA1c testing as a standard component of evaluation. Early identification of UDM allows for timely initiation of glycemic control, which has been shown to improve cardiovascular outcomes [1-8]. Research also plays a crucial role in addressing this issue. While several studies have explored the prevalence of UDM in ACS patients, there remains a need for large, multicenter studies that can provide more representative data across different regions of Pakistan. Additionally, longitudinal studies are required to assess the long-term impact of UDM on cardiovascular outcomes and to evaluate the effectiveness of screening and intervention strategies [1-8]. Undiagnosed diabetes mellitus represents a silent yet significant contributor to the burden of acute coronary syndrome in Pakistan. The high prevalence of UDM, coupled with its association with adverse cardiovascular outcomes, underscores the urgent need for improved screening and early detection strategies. Integrating HbA1c testing into routine ACS management, strengthening primary care systems, and enhancing public awareness are critical steps toward addressing this hidden epidemic. Without timely intervention, UDM will continue to fuel the already growing burden of cardiovascular disease in Pakistan, with profound implications for both individual patients and the healthcare system as a whole [9]. References Aamir AH, Ul-Haq Z, Mahar SA, Qureshi FM, Ahmad I, Jawa A, et al. Diabetes prevalence survey of Pakistan (DPS-PAK): prevalence of type 2 diabetes mellitus and prediabetes using HbA1c. BMJ Open. 2019;9(2):e025300. DOI: 10.1136/bmjopen-2018-025300 Basit A, Fawwad A, Qureshi H, Shera AS. Prevalence of diabetes, pre-diabetes and associated risk factors: second National Diabetes Survey of Pakistan (NDSP 2016–2017). BMJ Open. 2018;8(8):e020961. DOI: 10.1136/bmjopen-2017-020961 American Diabetes Association. Classification and diagnosis of diabetes: Standards of Medical Care in Diabetes—2024. Diabetes Care. 2024;47(Suppl 1):S20–S42. DOI: 10.2337/dc24-S002 Norhammar A, Tenerz Å, Nilsson G, Hamsten A, Efendíc S, Rydén L, et al. Glucose metabolism in patients with acute myocardial infarction and no previous diagnosis of diabetes mellitus: a prospective study. Lancet. 2002;359(9324):2140–4. DOI: 10.1016/S0140-6736(02)09089-X Kazim AH, Sheikh MA, Ali N, Ahmed N. Frequency of undiagnosed diabetes mellitus in patients presenting with acute coronary syndrome. Pak J Med Health Sci. 2022;16(5):5-9. DOI: 10.53350/pjmhs221695 Safdar T, Khan MA, Rehman AU, et al. Prevalence and impact of undiagnosed diabetes mellitus in patients with acute coronary syndrome. J Popul Ther Clin Pharmacol. 2025;32(1):1643-9. DOI: 10.53555/jptcp.v31i5.6399 Basit A, Fawwad A, Abdul Basit K, Waris N, Tahir B, Siddiqui IA; NDSP members. Glycated hemoglobin (HbA1c) as diagnostic criteria for diabetes: the optimal cut-off points values for the Pakistani population; a study from second National Diabetes Survey of Pakistan (NDSP) 2016-2017. BMJ Open Diabetes Res Care. 2020;8(1):e001058. DOI: 10.1136/bmjdrc-2019-001058 Kosiborod M, Rathore SS, Inzucchi SE, Masoudi FA, Wang Y, Havranek EP, et al. Admission glucose and mortality in elderly patients hospitalized with acute myocardial infarction: implications for patients with and without recognized diabetes. Circulation. 2005;111(23):3078-86. DOI: 10.1161/CIRCULATIONAHA.104.517839 Khan J, Khan MF, Khan K, Gul S, Ullah Q, Qadus N. Undiagnosed Diabetes Mellitus in Patients Presenting with Acute Coronary Syndrome: Frequency and Association with In-Hospital Outcomes. Pak Heart J. 2026;59(02):355-61. DOI: 10.47144/phj.v59i2.3551