Use of HbA1c to diagnose type 2 diabetes mellitus among high risk Sri Lankan adults

Ethnicity Affects A1C Levels in Patients With Diagnosed Type 2 Diabetes in Southern Israel

Purpose

To assess whether ethnicity affects the association between A1C and fasting glucose in people with type 2 diabetes.

Methods

This investigation was an epidemiological, cross-sectional study based on computerized medical records of the Southern District of Clalit Health Services. The study population comprised patients ≥40 years of age with type 2 diabetes who underwent blood tests between 8 August 2015 and 20 July 2020. A normal-error multiple linear regression model was used to assess differences in associations among ethnic groups (i.e., Arabs, Ethiopian Jews, and non-Ethiopian Jews) and A1C.

Results

A total of 59,432 patients with type 2 diabetes were included in the study. Of these, 1,804 were Jews of Ethiopian origin, 49,296 were non-Ethiopian Jews, and 8,332 were Arabs. Compared with non-Ethiopian Jews, A1C levels were increased by 0.1% (1 mmol/mol) among Ethiopian Jews and by 0.3% (3 mmol/mol) among Arabs. Ethnicity was a strong predictor of A1C, explaining 0.6% of its variance. An A1C level of 7% (53 mmol/mol) correlated with fasting glucose levels of 141, 136, and 126 mg/dL in non-Ethiopian Jews, Ethiopian Jews, and Arabs, respectively.

Conclusion

Ethnic differences in A1C should be considered by clinicians, researchers, and policymakers.

Prevalence of type 2 diabetes and pre-diabetes in Sri Lanka: a systematic review and meta-analysis

OBJECTIVE

The purpose of this research was to determine the prevalence of diabetes and pre-diabetes in Sri Lanka.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE (via PubMed), Web of Science, Sri Lankan Journals online and Google Scholar were searched for relevant articles published between January 1990 and June 2022 investigating the prevalence of pre-diabetes and diabetes in Sri Lanka.

METHODS

Random effect meta-analyses were conducted to derive the pooled prevalence of pre-diabetes and diabetes and their 95% CIs. Heterogeneity was explored by subgroup and meta-regression analyses. Sensitivity analyses were used to evaluate the impact of any single study on the pooled estimates. Two authors screened articles, extracted data and evaluated the quality of selected studies.

RESULTS

A total of 479 articles were reviewed, and 15 studies (n=30 137 participants) were selected in the final analysis. The overall pooled prevalence of diabetes was 12.07% (95% CI, 8.71% to 15.89%; prediction interval: 1.28-31.35). The pooled pre-diabetes prevalence was 15.57% (95% CI, 9.45% to 22.88%; prediction interval: 0.02-49.87). The pooled type 2 diabetes prevalence was the highest in the latest period of 2011-2021 (17.25%) than in the period of 2000s (11.84%) and 1990s (5.62%).

CONCLUSIONS

The growing trend of diabetes and pre-diabetes over the last 30 years is alarming in Sri Lanka. The government of Sri Lanka needs to take steps to improve diabetes education, screening, diagnosis and treatment.

PROSPERO REGISTRATION NUMBER

CRD42021288591.

Diagnostic accuracy of tests for type 2 diabetes and prediabetes: A systematic review and meta-analysis

AIM

This systematic review aimed to ascertain the diagnostic accuracy (sensitivity and specificity) of screening tests for early detection of type 2 diabetes and prediabetes in previously undiagnosed adults.

METHODS

This systematic review included published studies that included one or more index tests (random and fasting tests, HbA1c) for glucose detection, with 75-gram Oral Glucose Tolerance Test (or 2-hour post load glucose) as a reference standard (PROSPERO ID CRD42018102477). Seven databases were searched electronically (from their inception up to March 9, 2020) accompanied with bibliographic and website searches. Records were manually screened and full text were selected based on inclusion and exclusion criteria. Subsequently, data extraction was done using standardized form and quality assessment of studies using QUADAS-2 tool. Meta-analysis was done using bivariate model using Stata 14.0. Optimal cut offs in terms of sensitivity and specificity for the tests were analysed using R software.

RESULTS

Of 7,151 records assessed by title and abstract, a total of 37 peer reviewed articles were included in this systematic review. The pooled sensitivity, specificity, positive (LR+) and negative likelihood ratio (LR-) for diagnosing diabetes with HbA1c (6.5%; venous sample; n = 17 studies) were 50% (95% CI: 42-59%), 97.3% (95% CI: 95.3-98.4), 18.32 (95% CI: 11.06-30.53) and 0.51 (95% CI: 0.43-0.60), respectively. However, the optimal cut-off for diagnosing diabetes in previously undiagnosed adults with HbA1c was estimated as 6.03% with pooled sensitivity of 73.9% (95% CI: 68-79.1%) and specificity of 87.2% (95% CI: 82-91%). The optimal cut-off for Fasting Plasma Glucose (FPG) was estimated as 104 milligram/dL (mg/dL) with a sensitivity of 82.3% (95% CI: 74.6-88.1%) and specificity of 89.4% (95% CI: 85.2-92.5%).

CONCLUSION

Our findings suggest that at present recommended threshold of 6.5%, HbA1c is more specific and less sensitive in diagnosing the newly detected diabetes in undiagnosed population from community settings. Lowering of thresholds for HbA1c and FPG to 6.03% and 104 mg/dL for early detection in previously undiagnosed persons for screening purposes may be considered.

Demographic Associations of Diabetes Status by Both Fasting Plasma Glucose Concentration and Glycated Hemoglobin in a Community Survey in Galle District, Sri Lanka

Diagnostic tools used in detecting individuals with diabetes mellitus (DM) include fasting plasma glucose (FPG), glycated hemoglobin (HbA1C), and oral glucose tolerance test (OGTT). The present study was aimed to determine the demographic associations of diabetes status by both tests (FPG and HbA1C) in Galle district, Sri Lanka. 147 adults (30-60 years) who are having FPG ≥ 126 mg/dL underwent demographic evaluations and testing for HbA1C. Group 01 (diabetes status diagnosed by both tests) and group 2 (diabetes status diagnosed only by FPG) were compared using independant sample t-test and chi-square test. Logistic regression was used to study the association between the demographic factors and the diabetes status by both tests. Of the 147 study subjects, 38.1% were males, 61.9% were females, and 63.3% had a family history of diabetes among first-degree relatives (FDR). Mean age, body mass index (BMI), waist circumference (WC), FPG, and HbA1C of the participants were 48.4 ± 7.2 years, 25.1 ± 4.0 kg/m2, 88.8 ± 9.0 cm, 139.4 ± 30.1 mg/dL, and 6.4 ± 0.7%, respectively. The prevalence of diabetes based on both tests was 55.1%. There is a significant difference in mean BMI and WC while no significant differences in mean age between groups 01 and 02. No association was seen between gender and diabetes status (X 2(1) = 0.086, p=0.770), while a significant difference was observed between DM among FDR and diabetes status (X 2(1) = 33.215, p < 0.001). Significance of odds of having diabetes by both tests with rising BMI (OR = 1.97, CI 1.15-3.36, p=0.013) and DM among FDR (OR = 7.95, CI 3.54-17.88, p=0.000) was seen. We conclude rising BMI and having DM among FDR are strongly associated with diabetes status diagnosed by both tests of FPG and HbA1C in community screening.

Fasting Plasma Glucose and the HbA1c Are Not Optimal Screening Modalities for the Diagnosis of New Diabetes in Previously Undiagnosed Asian Indian Community Participants

Objectives

There is no definitive consensus on the screening algorithm in high-risk communities for diabetes. The aims of our study were to determine the prevalence of undiagnosed diabetes in a high-risk community using the oral glucose tolerance test (OGTT), as well as determine the value of anthropometric measurements and other measures of glycemia in the detection of diabetes.

Method

All participants from the Phoenix Lifestyle project without known diabetes, and who had undergone an OGTT were selected for study. Anthropometric measurements were collected according to accepted guidelines. Diabetes was diagnosed if fasting plasma glucose (FPG) ≥7.0 mmol/l, if 2-hour plasma glucose level during OGTT was ≥ 11.0 mmol/l, or if HbA1c ≥ 6.5%.

Results

The prevalence of newly diagnosed diabetes was 14.3% (11.7 % age standardized) (women=15.4%; men=11.8%). The prevalence rates were underestimated using FPG criteria, but overestimated when using the HbA1c. The AUC (area under the receiver-operator characteristics curve) was highest for FPG (.879), HbA1c (.855), then anthropometry measures (BMI=.621; waist circumference=.627). For diabetes, at levels >6.3, the discriminant ability (DA) of HbA1c was highest (79%), while a cut-point of ≥5.5mmol/l for FPG yielded a DA= 81.5% (82% sensitivity; 81%; specificity of 81%). There was a low level of agreement between the FPG (Kappa = .506), HbA1c (Kappa = .537), and the OGTT. Age- and sex-adjusted independent determinants of diabetes using stepwise backward logistic regression were age, triglyceride levels and a positive family history for diabetes.

Conclusion

Neither the HbA1c nor the FPG approached adequate predictive accuracy in the diagnosis of diabetes. In view of the high prevalence of undiagnosed diabetes, this study underscores the need for ongoing national surveillance data.