Glycemic parameters in patients with new-onset diabetes during COVID-19 pandemic are more severe than in patients with new-onset diabetes before the pandemic: NOD COVID India Study

BACKGROUND AND AIMS

It is not known if new onset diabetes during Coronavirus-19 disease (COVID-19; NOD COVID) is phenotypically or biochemically different than new onset diabetes before COVID-19 (NOD).

METHODS

All adults diagnosed with new onset diabetes from during the time of COVID-19 were compared with new onset diabetes prior to COVID-19 from two tertiary care hospitals in Chennai and Delhi. RTPCR test for SARS-CoV-2 virus was done as appropriate, and COVID-19 antibody test was done in all other NOD COVID patients.

RESULT

A total of 555 patients with new onset diabetes were included in the study (282 NOD and 273 NOD COVID patients). Patients with NOD COVID had higher fasting and post prandial blood glucose and glycated hemoglobin levels vs. NOD patients. Both the groups had high average body mass index; ∼28 kg/m². Interestingly, fasting C-peptide levels were significantly higher in the NOD COVID group vs. NOD group. There was no difference in C-peptide levels or glycemic parameters between the COVID-19 antibody positive and negative NOD COVID cases.

CONCLUSION

Individuals who were diagnosed with diabetes during COVID-19 epidemic (NOD COVID) do not significantly differ from those diagnosed before COVID-19 in symptomatology, phenotype, and C-peptide levels but they had more severe glycemia.

A Nutrigenetic Approach to Investigate the Relationship between Metabolic Traits and Vitamin D Status in an Asian Indian Population

Studies in Asian Indians have examined the association of metabolic traits with vitamin D status. However, findings have been quite inconsistent. Hence, we aimed to explore the relationship between metabolic traits and 25-hydroxyvitamin D [25(OH)D] concentrations. We investigate whether this relationship was modified by lifestyle factors using a nutrigenetic approach in 545 Asian Indians randomly selected from the Chennai Urban Rural Epidemiology Study (219 normal glucose tolerant individuals, 151 with pre-diabetes and 175 individuals with type 2 diabetes). A metabolic genetic risk score (GRS) was developed using five common metabolic disease-related genetic variants. There was a significant interaction between metabolic GRS and carbohydrate intake (energy%) on 25(OH)D (Pinteraction = 0.047). Individuals consuming a low carbohydrate diet (≤62%) and those having lesser number of metabolic risk alleles (GRS ≤ 1) had significantly higher levels of 25(OH)D (p = 0.033). Conversely, individuals consuming a high carbohydrate diet despite having lesser number of risk alleles did not show a significant increase in 25(OH)D (p = 0.662). In summary, our findings show that individuals carrying a smaller number of metabolic risk alleles are likely to have higher 25(OH)D levels if they consume a low carbohydrate diet. These data support the current dietary carbohydrate recommendations of 50%-60% energy suggesting that reduced metabolic genetic risk increases 25(OH)D.

Prevalence of vitamin D deficiency in urban south Indians with different grades of glucose tolerance

The present study assessed the prevalence of vitamin D deficiency in an urban south Indian population in individuals with different grades of glucose tolerance. A total of 1500 individuals (900 normal glucose tolerance (NGT), 300 prediabetes and 300 with type 2 diabetes mellitus (T2DM)) who were not on vitamin D supplementation were randomly selected from the Chennai Urban Rural Epidemiological Study follow-up study. Anthropometric, clinical examination and biochemical investigations (25-hydroxyvitamin D (25(OH)D), insulin, glycated Hb (HbA1c) and serum lipids) were measured. Vitamin D deficiency was defined as serum 25(OH)D < 20·0 ng/ml, insufficiency as 20-29·9 ng/ml and sufficiency as ≥30 ng/ml. Of the 1500 individuals studied, 45 % were males and the mean age was 46 (sd 12) years. Vitamin D levels lowered with increasing degrees of glucose tolerance (NGT: 21 (sd 11); prediabetes: 19 (sd 10); T2DM: 18 (sd 11) ng/ml, P < 0·001). The overall prevalence of vitamin D deficiency was 55 % and was significantly higher among individuals with T2DM (63 %) followed by prediabetes (58 %) and NGT (51 %) (Pfor trend < 0·001). Women had 1·6 times the risk of vitamin D deficiency compared with men (unadjusted OR 1·6 (95 % CI 1·3, 2·0) and adjusted OR 1·6 (95 % CI 1·2, 1·9)). However, there was no increasing trend observed with increasing age. The prevalence of abdominal obesity (66 v. 49 %), generalised obesity (80 v. 64 %), the metabolic syndrome (45 v. 37 %) and insulin resistance (38 v. 27 %) was significantly higher in those with vitamin D deficiency compared with those without. This study shows that vitamin D deficiency is highly prevalent in this urban south Indian population and was higher among individuals with T2DM and prediabetes compared with those with NGT.

Evidence for the association between FTO gene variants and vitamin B12 concentrations in an Asian Indian population

BACKGROUND

Low vitamin B12 concentrations have been associated with major clinical outcomes, including adiposity, in Indian populations. The Fat mass and obesity-associated gene (FTO) is an established obesity-susceptibility locus; however, it remains unknown whether it influences vitamin B12 status. Hence, we investigated the association of two previously studied FTO polymorphisms with vitamin B12 concentrations and metabolic disease-related outcomes and examined whether these associations were modified by dietary factors and physical activity.

METHODS

A total of 176 individuals with type 2 diabetes, 152 with pre-diabetes, and 220 normal glucose-tolerant individuals were randomly selected from the Chennai Urban Rural Epidemiology Study. Anthropometric, clinical, and biochemical investigations, which included body mass index (BMI), waist circumference, vitamin B12, homocysteine, and folic acid were measured. A validated food frequency questionnaire was used for dietary assessment and self-reported physical activity measures were collected. An unweighted genetic risk score (GRS) was calculated for two FTO single-nucleotide polymorphisms (rs8050136 and rs2388405) by summation of the number of risk alleles for obesity. Interaction analyses were performed by including the interaction terms in the regression model.

RESULTS

The GRS was significantly associated with increased BMI (P = 0.009) and risk of obesity (P = 0.023). Individuals carrying more than one risk allele for the GRS had 13.13% lower vitamin B12 concentrations, compared to individuals carrying zero risk alleles (P = 0.018). No associations between the GRS and folic acid and homocysteine concentrations were observed. Furthermore, no statistically significant GRS-diet or GRS-physical activity interactions with vitamin B12, folic acid, homocysteine or metabolic-disease outcomes were observed.

CONCLUSION

The study shows for the first time that a genetic risk score using two FTO SNPs is associated with lower vitamin B12 concentrations; however, we did not identify any evidence for the influence of lifestyle factors on this association. Further replication studies in larger cohorts are warranted to investigate the association between the GRS and vitamin B12 concentrations.

1,5 Anhydroglucitol in gestational diabetes mellitus

OBJECTIVE

1,5 Anhydroglucitol (1,5 AG) is reported to be a more sensitive marker of glucose variability and short-term glycemic control (1-2 weeks) in patients with type1 and type 2 diabetes. However, the role of 1,5 AG in gestational diabetes mellitus (GDM) is not clear. We estimated the serum levels of 1,5 AG in pregnant women with and without GDM.

METHODS

We recruited 220 pregnant women, 145 without and 75 with GDM visiting antenatal clinics in Tamil Nadu in South India. Oral glucose tolerance tests (OGTTs) were carried out using 82.5 g oral glucose (equivalent to 75 g of anhydrous glucose) and GDM was diagnosed based on the International Association of Diabetes and Pregnancy Study Group criteria. Serum 1,5 AG levels were measured using an enzymatic, colorimetric assay kit (Glycomark®, New York, NY). Receiver operating characteristic (ROC) curves were used to identify 1,5 AG cut-off points to identify GDM.

RESULTS

The mean levels of the 1,5 AG were significantly lower in women with GDM (11.8 ± 5.7 μg/mL, p < 0.001) compared to women without GDM (16.2 ± 6.2 μg/mL). In multiple logistic regression analysis, 1.5 AG showed a significant association with GDM (odds ratio [OR]: 0.876, 95% confidence interval [CI]: 0.812-0.944, p < 0.001) after adjusting for potential confounders. 1,5 AG had a C statistic of 0.693 compared to Fructosamine (0.671) and HbA1c (0.581) for identifying GDM. A 1,5 AG cut-off of 13.21 μg/mL had a C statistic of 0.6936 (95% CI: 0.6107-0.7583, p < 0.001), sensitivity of 67.6%, and specificity of 65.3% to identify GDM.

CONCLUSION

1,5AG levels are lower in pregnant women with GDM compared to individuals without GDM.

Prevalence of vitamin B12 deficiency in South Indians with different grades of glucose tolerance

AIMS

To determine the prevalence of vitamin B₁₂ deficiency in an urban south Indian population in individuals with different grades of glucose tolerance.

METHODS

A total of 1500 individuals [900 normal glucose tolerance (NGT), 300 prediabetes and 300 type 2 diabetes (T2DM)] who were not on vitamin B₁₂ supplementation were randomly selected from the Chennai Urban Rural Epidemiological Study (CURES) follow-up study. Anthropometric, clinical and biochemical investigations, which included vitamin B₁₂, insulin, homocysteine, HbA1c and serum lipids, were measured. Vitamin B₁₂ ≤ 191 pg/ml was defined as absolute vitamin B₁₂ deficiency and vitamin B₁₂ > 191 pg/ml and ≤ 350 pg/ml as borderline deficiency.

RESULTS

The mean levels of vitamin B₁₂ significantly decreased with increasing degrees of glucose tolerance (NGT 444 ± 368; prediabetes 409 ± 246; T2DM 389 ± 211 pg/ml, p = 0.021). The prevalence of absolute vitamin B₁₂ deficiency was 14.9% while 37.6% had borderline deficiency. The prevalence of absolute vitamin B₁₂ deficiency was significantly higher among individuals with T2DM (18.7%) followed by prediabetes (15%) and NGT(13.7%) [p for trend = 0.05]. The prevalence of vitamin B₁₂ significantly increased with age (p < 0.05) and in those with abdominal obesity (p < 0.001). Men and vegetarians had twice the risk of vitamin B₁₂ deficiency compared to women and non-vegetarians, respectively. Among individuals with NGT, prediabetes and T2DM, vitamin B₁₂ negatively correlated with homocysteine.

CONCLUSION

This study reports that the levels of vitamin B₁₂ decreased with increasing severity of glucose tolerance.

Association of serum vitamin D levels and diabetic retinopathy in Asian Indians with type 2 diabetes

BACKGROUND

Vitamin D deficiency (VDD) is a condition that has been associated with diabetic retinopathy (DR) in various populations, but has not been studied in Asian Indians.

AIMS

To evaluate the association of serum 25-hydroxyvitamin D (25(OH)D) levels with presence and severity of DR among Asian Indians with type 2 diabetes.

METHODS

We collected information on individuals with type 2 diabetes that received care at a tertiary diabetes centre in India, between 2012 and 2015. Patients were 18 years of age or older, underwent retinal examinations with DR severity grading and had serum 25(OH)D measurements.

RESULTS

Serum 25(OH)D levels were lower in patients with retinopathy compared to those without (11.9 ± 2.2 ng/ml vs. 13.7 ± 2.1 ng/ml, p < 0.001). Stratifying patients by DR grade, reduced geometric means of 25(OH)D levels were associated with increased retinopathy severity. After adjusting for six key covariates, VDD was associated with increased rates of proliferative DR (OR 2.05; 95% CI 1.35-3.11; p = 0.001).

CONCLUSIONS

In Asian Indians with type 2 diabetes, lower serum 25(OH)D was associated with increased severity of DR and the presence of VDD was associated with a two-fold increased risk for proliferative DR.

Relationship of glycemic control markers - 1,5 anhydroglucitol, fructosamine, and glycated hemoglobin among Asian Indians with different degrees of glucose intolerance

OBJECTIVE

1,5 anhydroglucitol (1,5 AG) is emerging as a marker of short-term glycemic control. We measured levels of 1,5 AG, fructosamine (FA), and glycated hemoglobin (HbA1c) in Asian Indians with different degrees of glucose intolerance.

MATERIALS AND METHODS

We recruited 210 individuals with normal glucose tolerance (NGT; n = 60), impaired glucose tolerance (IGT; n = 50), and Type 2 diabetes mellitus (T2DM; n = 100) from a large tertiary diabetes center in Chennai in Southern India. Anthropometric measurements were obtained using standardized techniques. Serum 1,5 AG (enzymatic colorimetric assay), FA (NBT/kinetic), and HbA1c (high-performance liquid chromatography) estimations were performed.

RESULTS

1,5 AG levels were significantly lower in the T2DM followed by IGT compared with the NGT group (7.9 vs. 18.8 vs. 21.8 µg/ml, P < 0.05). FA and HbA1c were higher in T2DM and IGT compared with NGT individuals (313 vs. 237 vs. 200 µmol/L, P < 0.001) (8.3 vs. 5.8 vs. 5.3%, P < 0.001).1,5 AG showed a significant negative correlation with FA (r = -0.618, P < 0.001) and HbA1c (r = -0.700, P < 0.001). 1,5 AG decreased with increasing quartiles of postprandial glucose (P for trend <0.001). However, even among individuals with HbA1c ≤7%, 27% individuals had decreased 1,5 AG plasma level (<10 µg/ml).

CONCLUSION

Circulatory levels of 1,5 AG correlate negatively with FA and HbA1c, and may provide an additional marker to assess glycemic control in patients with Type 2 diabetes.

Stability and reliability of glycated haemoglobin measurements in blood samples stored at -20°C

AIM

To validate the stability of glycated haemoglobin (HbA1c) measurements in blood samples stored at -20°C for up to one month.

METHODS

The study group comprised 142 type 2 diabetic subjects visiting a tertiary centre for diabetes at Chennai city in south India. The HbA1c assay was done on a fasting blood sample using the Bio-Rad Variant machine on Day 0 (day of blood sample collection). Several aliquots were stored at -20°C and the assay was repeated on the 3rd, 7th, 15th, and 30th day after the sample collection. Bland-Altman plots were constructed and variation in the HbA1c levels on the different days was compared with the day 0 level.

RESULTS

The median differences between HbA1c levels measured on Day 0 and the 3rd, 7th, 15th, and 30th day after blood collection were 0.0%, 0.2%, 0.3% and 0.5% respectively. Bland-Altman plot analysis showed that the differences between the day '0' and the different time points tend to get larger with time, but these were not clinically significant.

CONCLUSIONS

HbA1c levels are relatively stable up to 2weeks, if blood samples are stored at -20°C.