European Journal of Cardiovascular Medicine

Type 2 diabetes mellitus (T2DM) is a major public health challenge and one of the leading causes of morbidity and mortality worldwide. According to the International Diabetes Federation (IDF), approximately 589 million adults were living with diabetes globally in 2024, and this number is projected to rise to over 850 million by 2050, with the majority of cases attributed to T2DM [1]. India bears a disproportionate share of this burden, with an estimated nearly 90 million adults affected by diabetes, making it one of the countries with the highest prevalence worldwide [1,2]. The rising prevalence of T2DM in India has been accompanied by an increasing burden of microvascular complications such as diabetic nephropathy, retinopathy, and neuropathy, as well as macrovascular complications including coronary artery disease and cerebrovascular accidents, which significantly contribute to disability and premature mortality [3].

Magnesium is the fourth most abundant cation in the human body and plays a critical role in carbohydrate metabolism, insulin secretion, insulin receptor activity, and post-receptor insulin signaling. It also modulates vascular tone, endothelial function, oxidative stress, and inflammatory pathways, all of which are central to the pathophysiology of diabetic complications [4]. In patients with T2DM, magnesium deficiency is common and is attributed to reduced dietary intake, impaired intestinal absorption, and increased renal loss secondary to hyperglycemia and osmotic diuresis [5]. This creates a vicious cycle wherein hypomagnesemia worsens insulin resistance and glycemic control, further accelerating metabolic and vascular damage.

Several observational and meta-analytic studies have demonstrated a high prevalence of hypomagnesemia among patients with T2DM, ranging from 20% to over 40%, depending on the population studied [6]. Low serum magnesium levels have been consistently associated with poor glycemic control, higher HbA1c levels, and increased insulin resistance [7]. Importantly, emerging evidence suggests that hypomagnesemia may not only coexist with diabetes but also act as a predictive marker for the development of diabetic complications.

Clinical studies have reported significant associations between low serum magnesium levels and diabetic microvascular complications, particularly nephropathy, retinopathy, and neuropathy [8]. A recent meta-analysis demonstrated that patients with diabetic retinopathy had significantly lower serum magnesium levels compared to those without retinopathy, highlighting the potential role of magnesium in microvascular integrity [9]. Similarly, hypomagnesemia has been linked to increased risk of cardiovascular complications, endothelial dysfunction, and accelerated atherosclerosis in patients with T2DM [10].

Despite this growing body of evidence, serum magnesium estimation is not routinely incorporated into standard diabetes evaluation protocols in many clinical settings, particularly in resource-limited government hospitals. Furthermore, most available studies are cross-sectional in nature, limiting their ability to establish a temporal relationship between magnesium levels and the onset of diabetic complications. Prospective data from Indian populations, especially from tertiary care government hospitals, remain limited.

Therefore, this prospective study titled “Role of Serum Magnesium Levels in Predicting Complications in Type 2 Diabetes Mellitus”, conducted at PDU Medical College and attached group of Hospital (Dedraj Bhartiya Hospital -Churu), with a study population of 100 patients over a period of one year, aims to evaluate whether baseline serum magnesium levels can serve as a reliable biochemical predictor for the development of diabetic complications. Identifying such a marker could facilitate early risk stratification and targeted intervention, thereby improving long-term outcomes in patients with T2DM.

The present prospective study is designed to evaluate the clinical significance of serum magnesium levels in patients with Type 2 Diabetes Mellitus and their role in predicting the development of diabetic complications. The primary aim of this study is to assess baseline serum magnesium levels in patients with Type 2 Diabetes Mellitus and to determine their association with the occurrence of microvascular and macrovascular complications over the study period. The objectives include analyzing the prevalence of hypomagnesemia among diabetic patients, comparing serum magnesium levels between patients with and without diabetic complications, and examining the relationship between magnesium levels and commonly observed complications such as diabetic nephropathy, neuropathy, retinopathy, and cardiovascular manifestations. In addition, the study aims to evaluate whether low serum magnesium can serve as an early biochemical marker for identifying patients at higher risk of developing complications, independent of other clinical and metabolic parameters.

The future outcomes of this study are expected to contribute to improved risk stratification in patients with Type 2 Diabetes Mellitus by highlighting the prognostic value of serum magnesium estimation. Establishing a clear association between hypomagnesemia and diabetic complications may support the inclusion of serum magnesium assessment in routine diabetic evaluation protocols, particularly in resource-limited tertiary care settings. Furthermore, the findings may provide a rationale for early dietary counseling or magnesium supplementation as a preventive strategy, thereby potentially reducing the burden of diabetic complications and improving long-term clinical outcomes in diabetic populations.

This prospective observational study was conducted at PDU Medical College and attached group of Hospital (Dedraj Bhartiya Hospital -Churu), over a period of one year. The study included a total of 100 patients diagnosed with Type 2 Diabetes Mellitus, attending the outpatient and inpatient services of the Department of Medicine during the study period. Patients aged 18 years and above with a confirmed diagnosis of Type 2 Diabetes Mellitus, based on standard diagnostic criteria, were enrolled after obtaining written informed consent. Patients with chronic kidney disease stage 4 or higher, acute illness, chronic liver disease, thyroid disorders, malignancy, pregnancy, or those receiving magnesium supplementation or drugs known to alter magnesium levels were excluded to avoid confounding. Detailed clinical evaluation was carried out for all participants, including demographic details, duration of diabetes, treatment history, and assessment for diabetic complications. Microvascular complications such as diabetic nephropathy, retinopathy, and neuropathy were evaluated using standard clinical, laboratory, and ophthalmological criteria, while macrovascular complications were assessed based on clinical history, electrocardiography, and relevant imaging where indicated. Venous blood samples were collected under aseptic precautions after an overnight fast for estimation of serum magnesium and other routine biochemical parameters. Serum magnesium levels were measured using standard colorimetric methods in the central laboratory following quality control protocols. Hypomagnesemia was defined based on established laboratory reference ranges. All patients were followed prospectively during the study period to document the occurrence or progression of diabetic complications. The collected data were entered into Microsoft Excel and analyzed using appropriate statistical software. Categorical variables were expressed as frequencies and percentages, while continuous variables were summarized as mean and standard deviation. The association between serum magnesium levels and diabetic complications was assessed using the chi-square test or Student’s t-test as applicable. A p-value of less than 0.05 was considered statistically significant. The study was conducted after obtaining approval from the Institutional Ethics Committee, and all procedures adhered to ethical principles outlined in the Declaration of Helsinki.

The present prospective study evaluated the role of serum magnesium levels in predicting complications among patients with Type 2 Diabetes Mellitus. A total of 100 patients were included, with the majority belonging to the 40–59-year age group and males forming a higher proportion of the study population. Hypomagnesemia was observed in more than one-third of the patients. Diabetic complications were identified in just over half of the study participants, and a markedly higher proportion of these patients had low serum magnesium levels compared to those without complications. The prevalence of hypomagnesemia among patients with complications was substantially higher, indicating a strong association between reduced magnesium levels and the presence of diabetic complications.

The mean serum magnesium level was significantly lower in patients with diabetic complications compared to those without complications, highlighting the potential role of magnesium deficiency in the pathogenesis of diabetes-related end-organ damage. Duration of diabetes also showed a significant association with the presence of complications, with patients having a longer duration of disease demonstrating higher complication rates. In contrast, gender did not exhibit a statistically significant association with diabetic complications, suggesting that biochemical and disease-related factors play a more dominant role.

Overall, the findings indicate that hypomagnesemia is common in patients with Type 2 Diabetes Mellitus and is significantly associated with the presence of diabetic complications. Lower serum magnesium levels may serve as a useful biochemical marker for identifying patients at higher risk of developing complications, thereby supporting the potential role of routine magnesium assessment in the clinical management of diabetes.

Table 1. Demographic and Clinical Profile of Study Participants (n = 100)

Table 2. Comparison of Mean Serum Magnesium Levels in Patients With and Without Diabetic Complications

Table 3. Association of Serum Magnesium Levels with Diabetic Complications and Test of Significance (n = 100)

A statistically significant association was observed between serum magnesium status and the presence of diabetic complications. Hypomagnesemia was significantly more prevalent among patients with diabetic complications compared to those without complications (χ² = 11.42, p = 0.0007). Furthermore, the mean serum magnesium level was significantly lower in patients with complications (1.61 ± 0.22 mg/dL) than in those without complications (1.98 ± 0.26 mg/dL), and this difference was statistically significant (p < 0.001).

Figure 1: Distribution of Serum magnesium Levels in T2DM Patients

Figure 2: Association of Serum Magnesium Status with Diabetic Complication

In this study, hypomagnesemia was observed in 37% of patients with Type 2 Diabetes Mellitus, which is well within the range reported across diabetic cohorts. A recent hospital-based study (Abdullah et al., 2025) reported hypomagnesemia in 37.2% of participants, showing a near-identical burden to what was documented here, supporting the concept that magnesium deficiency is a common biochemical abnormality in routine diabetic care settings. [11] Broader evidence also indicates that hypomagnesemia is substantially more frequent in T2DM than in the general population, with cohort studies reporting prevalence varying widely (roughly ~9% to ~48%) depending on clinical setting, glycemic control, and comorbidity profile, which explains why institutional estimates often differ even within the same region. [12] Indian hospital-based studies have similarly reported prevalence in the same band; for example, one study noted 34% hypomagnesemia among T2DM patients, aligning closely with the present findings and reinforcing that this magnitude is clinically plausible in Indian tertiary-care populations. [13]

A key observation in this study was the significant association between hypomagnesemia and diabetic complications, where hypomagnesemia was markedly higher among those with complications compared to those without. This pattern is consistent with published literature showing that low magnesium status correlates with microvascular injury and diabetic end-organ damage. Lu et al. (2016) demonstrated that patients with microvascular complications such as albuminuria and/or retinopathy had significantly lower serum magnesium than those without these complications, suggesting magnesium deficiency may reflect or contribute to vascular and metabolic stress pathways involved in complication development. [14] Similarly, studies focused on diabetic retinopathy have repeatedly shown lower magnesium in complication groups; Kundu et al. (2013) reported mean magnesium around 1.38 mg/dL in patients with retinopathy compared with ~2.02 mg/dL in diabetics without retinopathy, which mirrors the direction of difference seen in this study where mean magnesium was lower in those with complications. [15] Taken together, this supports the idea that magnesium may act as a clinically useful “risk marker” for complication-prone diabetes, especially in routine OPD/IPD settings.

The present study also showed that mean serum magnesium was significantly lower in patients with complications, strengthening the biological plausibility of magnesium involvement in diabetic complication pathways. A large body of evidence supports magnesium’s role in insulin signaling, endothelial function, oxidative stress modulation, and inflammatory regulation—mechanisms that directly influence both microvascular and macrovascular outcomes. A Chinese cohort analysis and related epidemiologic work have similarly suggested that higher serum magnesium is associated with a lower risk of diabetic microvascular complications, supporting the directionality seen here. [16] In addition, systematic evidence indicates that magnesium deficiency is associated with a higher likelihood of diabetic retinopathy, and pooled data from multiple studies demonstrate significantly lower magnesium levels among those with retinopathy than those without. [17] These findings reinforce that lower magnesium is not merely a coincidental laboratory abnormality but may be linked to clinically meaningful outcomes.

Another important finding was that longer duration of diabetes was significantly associated with complications, which is expected because cumulative glycemic exposure and chronic metabolic injury are central determinants of microvascular and macrovascular damage. This observation is supported by comparative clinical studies that have reported progressively lower magnesium levels and higher complication rates with increasing diabetes duration, implying that long-standing diabetes may amplify magnesium depletion (through renal wasting and metabolic dysregulation) while simultaneously increasing complication risk. [18] Therefore, in practical terms, this study supports a combined risk lens—patients with longer duration of T2DM and low magnesium may represent a subgroup requiring closer complication surveillance, stronger metabolic control, and potentially corrective nutritional strategies.

This prospective study demonstrates that hypomagnesemia is a common biochemical abnormality among patients with Type 2 Diabetes Mellitus and is significantly associated with the presence of diabetic complications. Patients with complications showed markedly lower serum magnesium levels compared to those without complications, highlighting the potential role of magnesium deficiency in the pathogenesis and progression of diabetic end-organ damage. The findings suggest that serum magnesium may serve as a simple, inexpensive, and clinically useful biochemical marker for identifying patients at higher risk of developing diabetic complications, particularly in long-standing diabetes. Incorporating serum magnesium assessment into routine diabetic evaluation may aid in early risk stratification and improve overall disease management. Limitations Despite its strengths, this study has certain limitations. The sample size was relatively small and drawn from a single tertiary care center, which may limit the generalizability of the findings to broader populations. Serum magnesium was measured at baseline only, and intracellular magnesium levels, which may better reflect total body magnesium status, were not assessed. Additionally, dietary magnesium intake and urinary magnesium excretion were not evaluated, which could have provided further insight into the mechanisms underlying hypomagnesemia. The follow-up duration, although prospective, may not have been sufficient to capture the full spectrum of long-term diabetic complications. Recommendations Based on the study findings, routine screening of serum magnesium levels in patients with Type 2 Diabetes Mellitus is recommended, especially in those with long disease duration or poor glycemic control. Early identification and correction of hypomagnesemia through dietary modification or supplementation may help reduce the risk of diabetic complications. Larger multicentric studies with longer follow-up periods are recommended to confirm these findings and to establish causal relationships. Future research should also explore the role of magnesium supplementation as a preventive or therapeutic strategy in reducing the burden of diabetic microvascular and macrovascular complications.

1.       International Diabetes Federation. IDF Diabetes Atlas, 10th ed. Brussels: International Diabetes Federation; 2024.

2.       Anjana RM, Unnikrishnan R, Deepa M, et al. Metabolic non-communicable disease health report of India: the ICMR-INDIAB study. Lancet Diabetes Endocrinol. 2023;11(7):474-486.

3.       American Diabetes Association Professional Practice Committee. Standards of Care in Diabetes—2025. Diabetes Care. 2025;48(Suppl 1):S1-S350.

4.       Barbagallo M, Dominguez LJ. Magnesium and type 2 diabetes. World J Diabetes. 2015;6(10):1152-1157.

5.       Pham PC, Pham PM, Pham SV, et al. Hypomagnesemia in patients with type 2 diabetes. Clin J Am Soc Nephrol. 2007;2(2):366-373.

6.       de Valk HW. Magnesium in diabetes mellitus. Neth J Med. 1999;54(4):139-146.

7.       Guerrero-Romero F, Rodríguez-Morán M. Low serum magnesium levels and metabolic syndrome. Acta Diabetol. 2002;39(4):209-213.

8.       Sales CH, Pedrosa LFC. Magnesium and diabetes mellitus: their relation. Clin Nutr. 2006;25(4):554-562.

9.       Adiwinoto RP, Adiwinoto RD, Prajitno JH. Magnesium deficiency associated with diabetic retinopathy in type 2 diabetes mellitus: a meta-analysis. Int J Public Health Sci. 2021;10(3):565-573.

10.    Fang C, Wu W, Gu X, Dai S. Association of serum magnesium levels with cardiovascular disease in patients with type 2 diabetes. Nutrients. 2020;12(7):1918.

11.    Abdullah M, et al. Hypomagnesemia in Type 2 Diabetes: Study. 2025.

12.    Oost LJ, et al. Hypomagnesemia and cardiovascular risk in type 2 diabetes. Endocr Rev. 2023;44(3):357-377.

13.    Sahoo SK, et al. Serum magnesium in Type 2 diabetes and complications. Int J Adv Med. 2017;4(2):??-??.

14.    Lu J, et al. Serum magnesium concentration is inversely associated with albuminuria and retinopathy among patients with type 2 diabetes. 2016.

15.    Kundu D, Osta M, Mandal T, et al. Serum magnesium levels in patients with diabetic retinopathy. J Nat Sci Biol Med. 2013;4(1):113-116.

16.    Xiang X, et al. Reduced serum magnesium is associated with the risk of diabetic microvascular complications. Front Med. 2022;9:923282.

17.    Adiwinoto RP, et al. Magnesium deficiency associated with diabetic retinopathy in type 2 diabetes mellitus: a meta-analysis. Int J Public Health Sci. 2021;10(3):565-573.

18.  18.  Comparative study of serum magnesium levels in relation to diabetes duration and complications. J Pharmacol Ther Clin Pharmacol. 2023.