European Journal of Cardiovascular Medicine

Diabetes mellitus (DM) is a chronic, multifactorial metabolic disorder defined by persistent hyperglycaemia resulting from impaired insulin secretion, resistance to insulin action, or both. It is a principal contributor to global morbidity and mortality, largely through its long-term vascular complications, which include retinopathy, nephropathy, neuropathy, and cardiovascular disease [1]. As life expectancy increases worldwide, the prevalence of diabetes among older adults has become an escalating public health concern.

The epidemiological landscape of diabetes is undergoing a rapid transformation. The International Diabetes Federation (IDF) estimates that by 2045, 783 million adults will be living with diabetes, with the most substantial increases anticipated in low- and middle-income countries [2]. India, in particular, faces a burgeoning diabetes burden, projected to rise from 74 million cases in 2021 to reach 150  million by 2030 [2]. This epidemiological shift is paralleled by demographic changes, notably population ageing. The proportion of individuals aged 65 years and older in India has risen steadily, comprising 7.5% of the population as of 2017, and is expected to double in the coming decades [3]. In Odisha, this figure already stands at 8.3%, reflecting the pace of demographic transition in eastern India [4].

Older adults with diabetes present unique clinical challenges. Age-related physiological alterations—such as diminished renal function, impaired thirst mechanisms, and reduced β-cell reserve—render older individuals particularly susceptible to both hyperglycaemia and hypoglycaemia [5]. Additionally, atypical or non-specific presentations are common in this age group, with symptoms such as fatigue, altered mental status, recurrent infections, and falls frequently masking the underlying diabetic pathology [6]. Classical features like polyuria, polydipsia, and weight loss may be attenuated or absent, complicating timely diagnosis [7]. Furthermore, the risk of developing diabetic complications—both microvascular (e.g., nephropathy, neuropathy, retinopathy) and macrovascular (e.g., myocardial infarction, stroke, peripheral arterial disease)—increases with age and often presents concurrently with other geriatric syndromes such as cognitive impairment, urinary incontinence, and frailty [8–10].

Despite these complex and overlapping clinical presentations, there remains a paucity of data focused specifically on elderly individuals with diabetes in India, and particularly from the eastern states such as Odisha. Most existing studies are either community-based or fail to delineate age-specific nuances in presentation, comorbidity, and hospitalisation trends. This gap in the literature has implications for both clinical practice and public health planning.

The present study was designed to address this gap by examining the clinical spectrum of diabetes in individuals aged 65 years and older admitted to a tertiary care hospital in Odisha. The study aims to describe the prevalence of atypical presentations in newly diagnosed elderly patients, evaluate associated microvascular and macrovascular complications, assess common causes of hospitalisation, and explore relevant geriatric syndromes. Through this investigation, we aim to provide evidence that will support more nuanced, individualised care strategies for the growing population of elderly adults living with diabetes in India.

Study Design and Setting

This was a retrospective, hospital-based observational study conducted at Kalinga institute of medical sciences, a tertiary care academic and referral centre located in Bhubaneswar, Odisha, India. The study was carried out over a 12-month period, from April 2023 to March 2024. The study aimed to characterise the atypical clinical presentations, complication profiles, and patterns of hospitalisation among elderly patients with diabetes mellitus.

Study Population

The study population included all consecutive patients aged 65 years and older who were admitted to various medical and allied departments during the study period. A total of 710 elderly inpatients were screened, of whom 153 were found to have diabetes mellitus based on the American Diabetes Association (ADA) 2024 diagnostic criteria. These criteria included any of the following: a fasting plasma glucose level ≥126 mg/dL, a 2-hour plasma glucose ≥200 mg/dL during a 75-g oral glucose tolerance test, a glycated haemoglobin (HbA1c) level ≥6.5%, or a random plasma glucose ≥200 mg/dL in the presence of classic symptoms of hyperglycaemia or a hyperglycaemic crisis.

From the 153 diabetic patients identified, 100 patients being admitted due to some symptoms and complications and were evaluated. Eligibility for inclusion required patients to be aged 65 years or older, newly diagnosed to have diabetes fulfilling the definition diabetesCritically ill patients like known psychiatric illness, epilepsy, history of head injury, cerebral space-occupying lesions, hepatic encephalopathy, alcoholic liver disease, severe sepsis, complicated malaria, and end-stage organ failure were excluded. Patients with severely impaired cognition, unable to provide informed consent or history, were also excluded. Among 153 patients 53 patients were excluded due to either they were critically ill or were asymptomatic and denied evaluation.

Ethical Considerations

The study protocol was approved by the Institutional Ethics Committee of Kalinga institute of medical sciences, and all procedures adhered to ethical standards outlined in the Declaration of Helsinki. Written informed consent was obtained from all participants or their legally authorised representatives.

Data Collection

Data were collected using a structured clinical proforma. Demographic variables such as age, sex, residence (urban or rural), socioeconomic status, and religion were recorded. Clinical data included duration and type of diabetes, adherence to treatment, history of hypoglycaemic episodes, comorbidities, prior hospitalisation, and lifestyle-related factors including dietary habits, physical activity, smoking, and psychological stress.

Each participant underwent a thorough clinical examination including anthropometric measurements, assessment of vital signs, systemic evaluation, and focused neurological and geriatric screening. The body mass index (BMI) was calculated using standard methods.

Laboratory investigations included measurement of fasting blood glucose, post-prandial blood glucose, random blood sugar, HbA1c, serum urea and creatinine, lipid profile, liver function tests, serum electrolytes, and urinary ketones and albumin. Additional investigations such as urine culture, chest radiograph, ultrasonography of the abdomen and pelvis, ECG, and 2D echocardiography were performed as clinically indicated. In selected cases, advanced imaging such as CT brain and Doppler studies of peripheral vessels were used to evaluate vascular complications.

Clinical Assessment and Definitions

Microvascular complications were assessed using standard diagnostic tools. Diabetic nephropathy was defined by the presence of microalbuminuria (30–299 μg/mg creatinine) or serum creatinine >133 μmol/L, with or without macroalbuminuria. Retinopathy was identified using direct fundoscopy and retinal photography. Peripheral neuropathy was evaluated using a 128 Hz tuning fork for vibration perception and Semmes-Weinstein monofilament testing. Autonomic neuropathy was identified by clinical features such as orthostatic hypotension and gastrointestinal dysmotility.

Macrovascular complications included coronary artery disease (CAD), cerebrovascular accidents (CVA), and peripheral vascular disease (PVD). CAD was diagnosed based on a combination of clinical presentation, ECG findings, and echocardiographic abnormalities. CVA was defined by acute-onset focal or global neurological deficits confirmed by neuroimaging. PVD was diagnosed through clinical signs and confirmed with Doppler ultrasonography.

Cognitive function was assessed using a standardised 10-item mental status questionnaire evaluating orientation, memory, and awareness. A score with three or more errors indicated moderate to severe cognitive impairment. Urinary incontinence and recurrent falls were also documented as part of the geriatric profile.

Hypoglycaemia was defined as any symptomatic episode of low blood glucose (<50 mg/dL), confirmed biochemically or retrospectively through clinical records. Diabetic ketoacidosis (DKA) and hyperosmolar hyperglycaemic state (HHS) were identified using standard biochemical criteria and clinical presentation.

Statistical Analysis

All data were entered into a secure electronic database and analysed using IBM SPSS Statistics version 17.0. Continuous variables were summarised as mean ± standard deviation (SD), and categorical variables were presented as absolute frequencies and percentages. Inter-group comparisons were performed using Chi-square test or Fisher’s exact test for categorical data, and Student’s t-test, ANOVA, or Kruskal–Wallis test for continuous variables, as appropriate. A two-sided p-value of <0.05 was considered statistically significant.

Study Population Characteristics

Of the 710 elderly patients (aged ≥65 years) admitted during the study period, 153 (21.5%) were diagnosed with diabetes mellitus.. Detailed clinical and laboratory data were collected for 100 patients. The mean age of the study cohort was 70.7 ± 5.6 years. Nearly half (49.1%) of the diabetic patients were aged between 65 and 69 years, while 22.2% were aged 70–74, 17.6% were aged 75–80, and 11.1% were aged over 80 years. Males comprised 60% of the sample, with a male-to-female ratio of 1.5:1.

The majority of patients (55.5%) resided in rural areas, and 49.6% belonged to a low socioeconomic status. Regarding religious background, 90.8% were Hindu, followed by Muslim (5.9%) and Christian (3.3%) participants.

Lifestyle and Risk Factors

Common modifiable risk factors were prevalent across the cohort. A sedentary lifestyle was reported in 63% of patients, followed by psychological stress in 60%, and obesity (BMI ≥25 kg/m²) in 52%. The mean BMI was 24.1 ± 2.6 kg/m². Half of the patients consumed a non-vegetarian diet. Hypertension was present in 36% of participants, while a family history of diabetes was reported in 29%. Current smoking was noted in 22% of patients.

Atypical Presentations in Newly Diagnosed Elderly Patients

Of the 100 patients evaluated, 12 were newly diagnosed with diabetes during their current hospital admission. Atypical clinical features predominated in this group. The most frequently reported symptom was numbness, paraesthesia, or claudication of limbs, seen in 66.6% of cases. Altered mental status and nausea/vomiting were each observed in 58.3% of newly diagnosed patients. Chest pain and hemiparesis occurred in 50% of cases, and dyspnoea in 33.3%. Classical symptoms of diabetes—polyuria, polydipsia, and weight loss—were present in only 16.6% of cases.

Glycaemic Control and Biochemical Parameters

The mean fasting blood glucose was 167.7 ± 42.0 mg/dL, and mean postprandial blood glucose was 252.5 ± 63.6 mg/dL. The average HbA1c level was 8.37 ± 0.86%, indicating suboptimal long-term glycaemic control across the cohort. Laboratory parameters varied with diabetes duration; patients with a disease duration >10 years had significantly higher mean FBS (169.1 vs. 151.0 mg/dL; p=0.022), PPBS (255.5 vs. 225.0 mg/dL; p=0.016), and RBS (236.7 vs. 198.6 mg/dL; p=0.042) compared to those with <10 years of diabetes.

Acute Complications and Hypoglycaemia

Among the 88 patients with previously known diabetes, 35 (39.8%) reported at least one episode of severe hypoglycaemia in the preceding year. Hypoglycaemic episodes were more common among those aged ≥75 years (64.7% vs. 24.1%, p=0.042) and those with diabetes duration >10 years (42.6% vs. 30%). Insulin users had the highest prevalence of hypoglycaemia (42.2%), followed by oral antidiabetic drug (OAD) users (37.5%) and patients on combination therapy (36.3%). Irregular treatment adherence was also associated with a higher frequency of hypoglycaemic events (57.1% vs. 23.9% in regular users).

Causes of Hospitalisation

Hospitalisation was attributed to chronic diabetes-related complications in 51% of patients. Infections accounted for 31%, severe hypoglycaemia for 8%, and hyperglycaemic emergencies (DKA or HHS) for 7%. Among the chronic complication group, cerebrovascular accident (17%), acute myocardial infarction (15%), and chronic kidney disease requiring dialysis (15%) were the most frequent causes. Falls associated with diabetic neuropathy accounted for 4% of admissions, while anaemia secondary to diabetic nephropathy led to 2% of cases.

Among patients hospitalised for infections, respiratory tract infections were most common (38.7%), followed by urinary tract infections (32.3%), skin and soft tissue infections (22.6%), and gastrointestinal infections (6.5%).

Microvascular and Macrovascular Complications

Microvascular complications were prevalent in the cohort. Diabetic peripheral neuropathy was the most frequent, affecting 54% of patients. Diabetic nephropathy was diagnosed in 45%, and retinopathy in 24%. Autonomic neuropathy was present in 17% of patients. Age was not significantly associated with these complications, although there was a trend towards higher rates among patients aged ≥75 years.

Macrovascular complications were also common. Coronary artery disease (CAD) was present in 34% of patients, followed by cerebrovascular disease (CVD) in 25% and peripheral vascular disease in 12%. CAD was significantly more frequent in patients aged <75 years (21.2%) than those aged ≥75 years (5.9%) (p=0.048).

Geriatric Syndromes and Cognitive Impairment

Cognitive decline was identified in 31% of patients based on standard mental status testing, with 64.5% of those affected also having a prior history of cerebrovascular events. Urinary incontinence was observed in 29% of patients, and a history of repeated falls, with or without fractures, was reported in 19%. Female patients were more likely to report incontinence and falls, whereas cognitive impairment was slightly more common among males, though these differences were not statistically significant.

Comorbidities

Hypertension was the most prevalent comorbidity, present in 36% of patients. Depression was documented in 20%, and 15% of patients had both conditions concurrently. Chronic obstructive pulmonary disease (COPD) was present in 10% of patients, and pulmonary tuberculosis and malignancy were less frequent, noted in 4% and 1%, respectively.

Renal Function and Biochemical Profiles by Age and Sex

Mean serum urea and creatinine levels were higher among males compared to females, although not statistically significant. Patients aged ≥75 years had marginally higher levels of urea (62.8 vs. 51.5 mg/dL) and creatinine (3.06 vs. 1.94 mg/dL), indicating a trend toward greater renal dysfunction in older age groups.

This retrospective observational study provides a comprehensive overview of the clinical characteristics, atypical presentations, and complication burden of diabetes mellitus among elderly patients admitted to a tertiary care centre in eastern India. The findings reinforce the growing recognition that diabetes in older adults represents a distinct clinical entity, marked by heterogeneous symptomatology, frequent comorbidities, and an elevated risk of both acute and chronic complications.

The overall prevalence of diabetes among hospitalised elderly patients in our cohort was 21.5%, which is somewhat lower than the figures reported in other Indian hospital-based studies, such as those by Duran Alonso et al. (26.4%) and Puri et al. (27.1%) [11,12]. However, this variation may be explained by differences in study settings—our study was restricted to inpatients, whereas many others have drawn on community or outpatient populations. The predominance of type 2 diabetes mellitus (97.4%) aligns with national trends, confirming that type 2 diabetes continues to represent the overwhelming majority of cases among older adults in India [2,13].

The mean age of participants in our study was 70.7 years, with the largest proportion (49.1%) in the 65–69-year age group. This distribution mirrors national demographic trends that forecast a rapidly ageing population and a concomitant rise in elderly-onset diabetes. Male predominance (60%) and the greater representation of individuals from rural and low socioeconomic backgrounds are consistent with earlier studies conducted in similar Indian contexts [14,15].

One of the most striking observations in this study is the high prevalence of atypical clinical presentations among newly diagnosed elderly diabetics. Symptoms such as paraesthesia, altered mental status, and non-specific gastrointestinal complaints were more common than classical hyperglycaemic symptoms. These findings echo earlier reports from India and abroad that emphasise the “non-classical” nature of diabetes in older adults [16,17]. Lin et al. similarly noted that more than half of elderly diabetics presented with neurological symptoms or cognitive disturbances rather than thirst, polyuria, or weight loss [18]. In our study, only 16.6% of newly diagnosed diabetics reported classical symptoms, underscoring the need for heightened clinical vigilance in this population.

The burden of microvascular complications was considerable, with diabetic peripheral neuropathy affecting over half of the patients. This is broadly consistent with findings by Lili Husniati et al. (51.4%) and Wasan et al. (44.3%), suggesting that neuropathy is both highly prevalent and often under-recognised in older adults [19,20]. Diabetic nephropathy was present in 45% of cases, higher than the 30% reported by Lili Husniati et al., yet similar to figures from southern Indian studies [19,21]. Retinopathy was observed in 24% of participants—comparable to findings from Gadkari et al. (21.7%). [[22]. The high prevalence of complications even among relatively younger elderly (65–70 years) supports the hypothesis that age may not be the only determinant, and that factors such as poor glycaemic control and delayed diagnosis also play critical roles.

Our study also revealed a significant burden of macrovascular complications, notably coronary artery disease (34%) and cerebrovascular events (25%). These findings are similar to those reported by NHANES (CAD: 44%) and Ankush et al. (CAD: 34%, CVD: 25%) [1323]. Interestingly, the prevalence of CAD was slightly higher in patients under 75 years than those above, potentially reflecting survival bias or underdiagnosis in the older age group. Peripheral vascular disease was identified in 12% of patients, consistent with the rates reported by Lin et al. and Ankush et al. [18,23].

The acute complication profile in our cohort is also noteworthy. Hypoglycaemia occurred in nearly 40% of patients with known diabetes, with significantly higher rates among insulin users and those aged ≥75 years. These figures are lower than those reported by Hepburn et al. (55.3%) but remain clinically significant given the frailty and cognitive vulnerability of this age group [24]. DKA and HHS together accounted for 7% of hospitalisations, comparable to the 4.8% reported by Lin et al. [18]. The high rate of hypoglycaemia in insulin-treated elderly, as well as among those with longer disease duration or poor adherence, highlights the need for individualised glycaemic targets and treatment simplification in this age group.

Our analysis of hospitalisation causes demonstrated that chronic diabetic complications accounted for the majority of admissions (51%), followed by infections (31%), acute hypoglycaemia (8%), and hyperglycaemic crises (7%). These figures closely parallel findings by Duran Alonso et al. (55.1% chronic complications) and Lin et al. (42%) [11,18]. Among infectious causes, respiratory tract infections were most prevalent, followed by urinary tract infections and soft tissue infections—mirroring the immune vulnerability and reduced mucosal defence mechanisms described in older diabetics [25].

Geriatric syndromes—a defining characteristic of ageing with diabetes—were also prominent. Cognitive impairment was documented in 31% of patients, significantly associated with prior cerebrovascular events (64.5%). This is comparable to prevalence data from Corriere et al. and NHANES, both of which report cognitive dysfunction in roughly one-third of elderly diabetics [26,13]. Urinary incontinence (29%) and recurrent falls (19%) were also common, further complicating disease management and increasing the risk of hospitalisation and disability. These findings reaffirm the multifactorial vulnerability of older adults with diabetes and the need for integrated geriatric care models.

Finally, our study confirmed the high prevalence of comorbid conditions, particularly hypertension (36%) and depression (20%), which were often co-occurring. These results align with other Indian studies and highlight the syndromic clustering of non-communicable diseases in later life [12,14]. The additive effects of these comorbidities not only complicate clinical decision-making but also increase the risk of functional decline, polypharmacy, and health service utilisation.

Strengths and Limitations

The strengths of this study lie in its comprehensive evaluation of both clinical and biochemical profiles, as well as its focus on an under-researched demographic from eastern India. To our knowledge, this is among the few studies in the region to evaluate atypical presentations, geriatric syndromes, and hospitalisation causes in elderly diabetics.

However, the study is limited by its retrospective design, which may be prone to selection and information bias. Cognitive assessment relied on a simple mental status questionnaire rather than a full neurocognitive battery. The findings, though robust, may not be generalisable to community-dwelling elderly or non-hospitalised populations.

Implications for Clinical Practice

The findings from this study underscore the complexity and heterogeneity of diabetes in older adults. Clinicians should maintain a high index of suspicion for atypical symptoms and aim for early detection through proactive screening, particularly in those with non-specific neurological or infectious presentations. Management strategies must be individualised, balancing glycaemic targets with risk of hypoglycaemia and functional impairment. The integration of geriatric principles—including fall risk screening, cognitive assessment, and deprescribing—into diabetes care models is essential to improve outcomes in this growing population.

This study highlights the distinct and multifaceted nature of diabetes mellitus in the elderly, particularly within the Indian hospital setting. Among older adults, diabetes frequently presents with atypical, non-classical symptoms—most notably neurological disturbances and cognitive changes—often delaying diagnosis and contributing to an increased burden of both microvascular and macrovascular complications. Chronic complications, recurrent infections, geriatric syndromes, and a high incidence of hypoglycaemia were significant contributors to hospitalisation and morbidity in this population.

The findings underscore the need for heightened clinical awareness, early screening for non-traditional presentations, and comprehensive geriatric assessments as part of routine diabetes care in the elderly. Treatment strategies must be individualised, balancing glycaemic control with the risks of hypoglycaemia, comorbid conditions, cognitive function, and functional status. Integration of geriatric principles into diabetes management, alongside multidisciplinary care, is essential to improve outcomes and preserve quality of life in this growing and vulnerable demographic.

Further prospective, multicentre studies are warranted to deepen our understanding of diabetes in ageing populations across diverse sociocultural and healthcare contexts in India.

Table 1: Demographics, risk Factors, and presenting symptoms of elderly newly diagnosed hospitalized diabetic patients(n=153)

Table 2 : Clinical Complications and hospitalization causes (n=100)

Table 3: Cognitive decline and comorbidity in elderly diabetics

Figure 1: Causes of Hospitalization

Figure 2: Prevalence of Microvascular and macrovascular Complications

Figure 3: Lifestyle and Clinical Risk factors

Figure 4: Geriatric Syndromes by sex

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