Study of Glycemic Variability in Well-controlled Type 2 Diabetic Patients Using Continuous Glucose Monitoring System.

INTRODUCTION: The world has changed tremendously for patients suffering from diabetes mellitus with the development of cutting-edge technologies like continuous glucose monitoring and flash glucose monitoring systems. Now, the details of constant fluctuations of glucose in their blood can be monitored not only by medical professionals but also by patients, and this is called glycemic variability (GV). Traditional metrics of glycemic control measurement, such as glycated hemoglobin (HbA1c), fail to reflect various short-term glycemic changes like postprandial hyperglycemia and hypoglycemic episodes, paving the way to the occurrence of various diabetic complications even in asymptomatic, well-controlled diabetic patients. This need for advanced management of diabetes and effective monitoring of these swings in blood glucose can be met by using a continuous glucose monitoring system (CGMS). AIM AND OBJECTIVE: To evaluate the extent of GV in well-controlled type 2 diabetes mellitus (T2DM) patients using a flash CGMS and to assess the correlation between GV and HbA1c. MATERIALS AND METHODS: A hospital-based prospective observational study was carried out from May 2020 to Oct 2021 at the Department of Medicine, SMS Hospital, Jaipur, Rajasthan (India), after approval from the Ethics Committee of the institution. A total of 30 patients with well-controlled T2DM (HbA1c was ≥6.5, but ≤7.5) were included in the study using simple random techniques after written informed consent from patients. Patients were studied for glycemic excursions over a period of 7 days by using FreeStyle® Libre Pro™, which is a flash glucose monitoring system. The CGM sensor was attached to the left upper arm of the patient on day 0 and removed on day 7. The data recorded in the sensor was then retrieved using pre-installed computer software and analyzed using standard CGM metrics like standard deviation (SD), percentage coefficient of variation (%CV), time above range (TAR), time below range (TBR), and time in range (TIR), out of which %CV was used to quantify GV. %CV has been used to cluster patients into four cohorts from best to worst, namely: best/low CV ≤ 10%, intermediate CV from 10 to 20%, high CV from 20 to 30%, and very high CV of >30%. Scatterplots are used to establish correlations between various parameters. RESULT: Data from a total of 30 patients were analyzed using CGMS and thus used for calculating standard CGM metrics; glucose readings every 15 minutes were recorded consecutively for 7-day periods, making it a total of 672 readings for each patient. Interpreting the CGM data of all 30 patients, the following results were found: the mean blood glucose of all cases is 134.925 ± 22.323 mg/dL, the mean SD of blood glucose of all cases is 35.348 ± 9.388 mg/dL, the mean of %CV of all cases is 26.376 ± 6.193%. CGM parameters of time are used in the form of percentages, and the following results were found: the mean of TAR, TBR, and TIR is 14.425 ± 13.211, 5.771 ± 6.808, and 82.594 ± 12.888%, respectively. Clustering the patients into cohorts, the proportion of patients exhibiting best/low %CV (10%) is 0, intermediate %CV (10-20%) is 16.67% (five out of 30 patients), high %CV (20-30%) is 50% (15 out of 30 patients) and very high %CV (>30%) is 33.33% (10 out of 30 patients). Also, there is no significant correlation found between HbA1c and %CV (ρ = 0.076, p-value = 0.690); a significant negative correlation was found between %CV and TIR (ρ = -0.604, p < 0.001S); a positive correlation of %CV with TAR and TBR is significant (ρ = 0.816, p-value of <0.001). CONCLUSION: Using a flash CGMS device and considering %CV as the parameter and primary measure of GV, the study demonstrated the overall instability of a person's glycemic control, making note of unrecognized events of hypoglycemia and hyperglycemia in asymptomatic well-controlled T2DM patients, revealing the overall volatile glycemic control. The most important finding of this study is that even those diabetics who are considered well-controlled experience a great degree of GV as assessed by CGM-derived metrics. This study also demonstrated that there is no significant correlation between HbA1c and GV, suggesting that patients may not have optimal control of their diabetes despite having "normal HbA1c" values; hence, GV can be considered an HbA1c-independent danger factor, having more harmful effects than sustained hyperglycemia in the growth of diabetic complications. So, by using CGM-derived metrics, the measurement of GV has the potential to complement HbA1c data. In this manner, a more comprehensive assessment of glycemic excursions can be provided for better treatment decisions, thereby facilitating optimal glycemic control, which is essential for reducing overall complications and promoting good quality of life.

Type 1 Renal Tubular Acidosis with Hypokalemic Quadriparesis in Sjogren Syndrome.

Sjogren syndrome is an autoimmune disease characterised by lymphocytic infiltration and inflammation of the exocrine glands resulting in decreased secretion of involved glands which manifests mostly as dry eye and dry mouth. The prevalence of the disease is reported to be about 10.3 per 10,000 population. It is more common in females with a male: female ratio of 16:1. Extra glandular manifestations are seen in up to 1/3rd of the cases. Renal involvement is seen in 4.9% of patients with Sjogren syndrome. MATERIAL: Here we present three cases of Sjogren Syndrome who presented to our hospital with hypokalaemic quadriparesis. OBSERVATION: On evaluation all three of the patients were found to have renal tubular acidosis type 1. None of these patients had any symptom of Sjogren syndrome before the onset of quadriparesis. All of these patients had acute onset progressive areflexic quadriparesis with involvement of facial muscles and drooping of eyelids without sensory or bladder bowel involvement. One of these patients had respiratory muscle paralysis severe enough to mandate mechanical ventilation. Arterial Blood Gas analysis and urine electrolyte analysis were suggestive of type 1 renal tubular acidosis. ANA positive in 2 of the 3 patients. Anti-SSA & anti-SSB antibodies were positive in all three patients. Supportive measures and IV fluid and electrolyte correction was done. There was complete recovery of power in all three patients and were discharged on oral medications.Renal Tubular Acidosis is characterised by inability of the nephrons to maintain physiologic acid base balance. This usually results from a defect in the tubular transport mechanisms. Distal Renal tubular acidosis (as in these patients) is further defined by an alkalotic urinary pH(>5.5) and profound hypokalemia due to impairment in H+ secretion in ditstal tubular alpha-intercalated cells. Owing to this imbalance of ionic transport in distal tubules there can be nephrocalcinosis, nephrolithiasis, rickets and severe muscle weakness. Sjogren syndrome is one of the etiologies leading to development of T1RTA.T1RTA can be the presenting feature of Sjogren Syndrome. CONCLUSION: Though a rare manifestation of the disease if can be the presenting symptom. Work up for RTA (ABG, urine electrolytes, Urine PH and osmolarity etc) in patients with hypokalaemic paresis can help establish the etiological diagnosis(ANA, anti-SSA,anti-SSB) and help prevent future relapses of the disease.