Diabetes mellitus (DM) is a group of metabolic disorders characterized by hyperglycemia. It is rapidly emerging as an important cause of mortality and morbidity in developing countries. According to the International Diabetes Federation, the number of affected patients in 2019 stands at 463 million. It is estimated that by 2045, around 700 million people will suffer from diabetes [1–3]. In 2021, it is estimated that 537 million people have diabetes, and this number is projected to reach 643 million by 2030, and 783 million by 2045. In addition, 541 million people are estimated to have impaired glucose tolerance in 2021. It is also estimated that over 6.7 million people aged 20–79 will die from diabetes-related causes in 2021 [4]. According to the World Health Organization, noncommunicable diseases accounted for 74% of deaths globally in 2019, of which, diabetes resulted in 1.6 million deaths, thus becoming the ninth leading cause of death globally [5]. In the month of December 2019, the first pneumonia cases of unknown origin were identified in China [6] and spread around the world [7]. DM is a well-known risk factor for worse clinical outcomes in patients with coronavirus disease 2019 (COVID-19). However, the relationship between these two ailments seems to be interlinked. The COVID-19 pandemic and post-COVID-19 era have significantly affected blood glucose control in patients with DM [8]. Patients infected with COVID-19 have exhibited remarkable metabolic changes, including significant increases in blood glucose. It is attributable to the increased release of cytokines and inflammatory mediators, which led to an increase in insulin resistance and the hyperglycemia that accompanied it [9]. Furthermore, it has been hypothesized that COVID-19 may play a role in the development of acute DM in certain patients by targeting angiotensin-converting enzyme 2 receptors in pancreatic islets, resulting in pancreatic injury [10]. While treating COVID-19, the drugs like glucocorticoids could improve insulin resistance and glycemic dysregulation [11]. Hence, the inconsistent regulation of glycemic levels in diabetics following COVID-19 infection needs to be explored well.

Table 1 represents the demographic details of study participants. A total of 50 subjects were recruited in this present study with 25 males and 25 females. The mean and SD of age (years), BMI (kg/m²), and total cholesterol (mg/dl) were 53.44 ± 10.05, 27.72 ± 5.17, and 132 ± 19.75. In our study, there are 34%–46% of subjects are with an age range of 41–60 years. The mean duration of diabetes was 8 years. Nearly, 50%–40% of the subjects were not following the diet and physical exercise. 62% of the subjects were having elevated triglycerides. Along with TDM, 46% of subjects were having other co-morbidities. Table 2 depicts the T2DM subjects of pre-COVID-19 (n=31) and post-COVID-19 (n=19) glycemic parameters are depicted. It was noticed that the glycemic parameters such as Fasting Blood sugar (FBS), Post Prandial blood sugar (PPBS), and HbA1c levels are highly significantly dysregulated compared to pre-COVID-19. A significant association was noticed between steroidal use and an increase in FBS levels (p < 0.05) (Table 3). There are 28 subjects who were exposed to steroids and 21 are unexposed. The steroidal exposure group was significantly linked to secondary infections (p < 0.05) (Table 4).

The novel severe acute respiratory distress syndrome-coronavirus 2 (SARS-CoV-2) has caused one of the most substantial pandemics that has affected humanity in the last century [12]. Diabetes is a common comorbidity associated with COVID-19. It appears that older individuals and those with pre-existing medical conditions such as DM, heart disease, and asthma are more susceptible to becoming severely ill from the COVID-19 virus [13,14]. In the deluge of drugs being used for COVID-19 infection, glucocorticoids (GCs) stand out by reducing mortality among in-hospital severe-to-critically ill patients [15–17]. The relationship between the severity of COVID-19 outcomes in individuals with diabetes and the level of hyperglycemia prompts an inquiry into whether this connection signifies a causal link. Alternatively, it may suggest that the severity of the illness in people with diabetes is a dual factor, contributing to both heightened blood glucose levels and an elevated risk of mortality. Current reports from diverse datasets present conflicting perspectives on this issue [18].

Hypoglycemia emerges as a notable risk factor for unfavorable outcomes in intensive care [19]. Concerning the glucagon-like peptide-1 receptor agonist and sodium–glucose transporter 2 inhibitor classes, individuals could potentially forego crucial cardiorenal advantages associated with these agents [20,21]. The lockdown because of the COVID-19 pandemic adversely affected body weight and glucose control in T2DM patients, specifically in those on insulin treatment [22]. In our study, BMI (kg/m²) and total cholesterol (mg/dl) was significantly affecting the glycemic levels. A single-center study noticed that, after 8 weeks of lockdown, an increase of HbA1c > 0.3% was observed in 26% of participants, and triglycerides were persistently elevated [23]. The levels were also significantly dysregulated compared to the pre-COVID-19 period, in our study. However, the study conducted in Turkey, revealed that the changes in glycaemic parameters between pre- and post-lockdown were not statistically significant [24]. The association between corticosteroid administration and a higher incidence of glycemic dysregulation was noticed in mechanically ventilated COVID-19 patients [25]. In our study, the steroidal exposure group was significantly linked to increased glycemic levels and secondary infections. The findings of the systematic review and meta-analysis have demonstrated that the COVID-19 lockdown resulted in a significant increase (p < 0.05) in the levels of glycated hemoglobin, fasting glucose, and body mass index in patients with type 2 diabetes [26]. The incidence of hypertriglyceridemia is high (60%) in our study. Hypertriglyceridemia is a well-recognized cause of angina pectoris and metabolic disorders, and it is frequently observed in the presence of severe hyperglycemia [27,28]. A pathogenetic function for COVID-19 is unclear. It is not possible to rule out the possibility that T2DM, hypertriglyceridemia, and COVID-19 are merely coincidental, and they could be managed with strict lifestyle modifications [29,30]. Overall, in this study, glycemic parameters show a significant increase while comparing pre and post-COVID-19 data. Continuous glucose monitoring, appropriate pharmacotherapy, and lifestyle interventions could prevent further organ damage.

In the present study, we found that glycemic parameters like FBS, HbA1c, and PPBS show significant increases while comparing pre- and post-COVID-19 data. This study also concludes that there is a relationship that exists between steroid use and an increase in blood sugars, and steroid use and secondary infections and also increase in blood sugars and secondary infections. Elevated blood sugars may increase the risk of secondary infections in both pre- and post-COVID-19 patients. Hence monitoring of blood sugars may show a significant change in risk of secondary infections and decrease the mortality in patients with diabetes.

All the authors are thankful to Asters Ramesh Hospital management, for providing the access to conduct this study.

The authors declare that they have no conflict of interest.

The study procedure was approved by the Institutional Ethics Committee of Asters Ramesh Hospital, Guntur, AP, India. Dated: 25.01.2022, (IEC/25/JAN/174). Informed consent was obtained from all subjects and the study was conducted in accordance with the declaration of Helsinki, good clinical practice guidelines.

All data generated or analyzed during this study are included in this published article.