The changing relationship between HbA1c and FPG according to different FPG ranges

Correlation between inflammatory biomarkers, cognitive function and glycemic and lipid profiles in patients with type 2 diabetes mellitus: A systematic review and meta-analysis

This study aimed to quantitatively estimate the correlation between systemic inflammation with cognitive function, as well as glycemic and lipid profiles in patients with type 2 diabetes mellitus (T2DM). The PubMed, Web of Science, EMBASE, SCOPUS, CNKI, Wanfang, VIP, and CBM databases were searched from its inception until June 2023 (PROSPERO registration: CRD42022356889). We analyzed data extracted from observational studies to quantify the correlations (r) as the pooled effect size and further performed subgroup analyses and sensitivity analyses. A total of 32 studies involving 7,483 patients with T2DM were included. The findings revealed a significant moderate negative correlation between interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP) levels with Montreal Cognitive Assessment scores. TNF-α levels also had moderate negative correlation with Mini-Mental State Examination scores. For glycemic and lipid profiles, there was a significant moderate positive correlation between CRP and TNF-α levels and glycated hemoglobin (HbA1c), and TNF-α levels were also found to be lowly positively correlated with fasting blood glucose (FBG). CRP levels were found to have a low positive correlation with total cholesterol (TC), and IL-6 levels were found to be lowly positively correlated with triglycerides. The results indicate that elevated levels of IL-6, CRP, and TNF-α are significantly associated with cognitive impairment in patients with T2DM and may serve as inflammatory markers for T2DM with mild cognitive impairment. The CRP and TNF-α levels were more strongly correlated with HbA1c than with FBG and TC. Further research is needed to determine the clinical value of these inflammatory biomarkers and to investigate potential causal mechanisms underlying this association.

Correlation between Estimated Average Glucose Levels Calculated from HbA1c Values and Random Blood Glucose Levels in a Cohort of Subjects

Objective Hemoglobin A1c (HbA1c) level remains the gold standard test for the assessment of glycemic control, and it reflects the mean glucose values in the previous 3-month period. HbA1c is expressed as a percentage, whereas the monitoring and treatment of diabetes are based on blood glucose levels expressed as mg/dL. It is appropriate to make it easy for the patient to understand both random blood sugar (RBS) and estimated average glucose (eAG) expressed with the same units. This will enhance the usefulness of eAG. This article determines the statistical correlation between eAG derived from HBA1C with RBS values both in diabetic and prediabetic subjects.

Methods The RBS and HbA1c levels of 178 males and 283 females (12–90 years) were obtained and the eAG levels were calculated using Nathan's regression equation. The samples were divided into four groups based on HbA1c levels—group 1: HbA1c greater than 9%, group 2: HbA1c 6.5 to 9%, group 3: HbA1c 5.7 to 6.4%; and group 4: HbA1c less than 5.7%.

Results There was a statistically significant positive correlation between RBS and eAG values for the study group 1 and 2. Also, the median values of RBS and eAG showed a significant difference (p < 0.001).

Conclusion As the association between the RBS and eAG levels is strong in a fairly and poorly controlled diabetic population, reporting the eAG level together with the HbA1c level at no additional cost may assist in effective blood glucose control in clinical care. However, eAG and RBS values cannot be used interchangeably.

Lifestyle Improvements and Vitamin D Supplementation Play an Important Role in the Prevention of Childhood Diabetes

Objective

This study was to investigate the characteristics of insulin secretion and the 25-hydroxyvitamin D3 (25(OH)D3) levels in children with obesity.

Methods

A retrospective analysis was conducted among children who underwent health checkups in the pediatric healthcare department of our hospital from January 2018 to January 2021, and they were divided into a normal group and an obese group according to their BMI. The insulin secretion and the 25(OH)D3 levels of the two groups of children were compared. A total of 721 children were included in the study, including 591 in the normal group and 130 in the obese group, with an obesity rate of 18.03%.

Results

The blood glucose of the normal group was 4.55 ± 1.75 mmol/L, and the 2 h PG was 7.51 ± 2.11 mmol/L; in the obesity group, they were 6.03 ± 2.16 mmol/L and 8.92 ± 3.24 mmol/L, respectively. The FPG and 2 h PG in the obese group were significantly higher than those in the normal group (all P < 0.05). The incidence of IFG/IGT in the normal group was 5.24% (31/591), and the incidence of DM was 3.71% (22/591); the incidence of IFG/IGT in the obese group was 14.62% (19/130), and the incidence of DM was 13.08% (17/130). The incidences of IFG/IGT and DM in the obese group were significantly higher than those in the normal group (P < 0.05). The FINS of the children in the normal group was 18.46 ± 3.15 μU/mL, and the HOMA-IR was 2.64 ± 0.62; the above indicators in the obese group were 19.11 ± 4.72 μU/mL and 3.01 ± 0.83, respectively. The FINS and HOMA-IR in the obese group were significantly higher than those in the normal group (P < 0.05). The serum 25(OH)D3 level in the normal group was 28.15 ± 5.27 ng/mL, of which 556 cases were normal in 25(OH)D3 and 35 cases were deficient in 25(OH)D3. The serum 25(OH)D3 level in the obese group was 24.35 ± 4.51 ng/mL, of which 112 cases were normal in 25(OH)D3 and 18 cases were deficient in 25(OH)D3. The level of serum 25(OH)D3 in the normal group was significantly higher than that in the normal group, and the ratio of 25(OH)D3 deficiency was significantly lower than that in the normal group (P < 0.05).

Conclusions

The blood glucose level of childhood obesity was significantly increased, the incidence of abnormal glucose metabolism and diabetes was significantly increased, and the level of 25(OH) vitamin D3 was significantly decreased. Lifestyle improvements and vitamin D supplementation play an important role in the prevention of childhood diabetes. Because the major causes of childhood obesity are excessive caloric intake and lack of exercise, the most effective and direct measures to prevent obesity are a reasonable lifestyle, reasonable eating habits, and moderate exercise. Although genetics are critical, there is no reliable way to eliminate obesity genes in the human body. Therefore, the role of obesity genes is required to be ultimately eliminated by reduced caloric intake and increased physical activity.

Relationship Between Estimated Average Glucose (eAG) and Fasting Plasma Glucose in a Cohort of Pakistani Diabetic Subjects

Introduction Scientific literature is scarce on the utility of estimated average glucose (eAG) from Pakistan. Hence, there is a dire need to evaluate the relationship between eAG and fasting plasma glucose (FPG), in order to enhance our understanding of eAG and its usefulness. This study aims to investigate the relationship between FPG and eAG in diabetic patients calculated using HbA1C. Materials and methods A retrospective study was conducted at the Aga Khan University, Karachi, Pakistan. The medical records of both genders in the age range of 18-60 years, presenting as outpatients at the endocrine clinic, labeled as DM, were reviewed from January 2013 to December 2019. The subjects were divided into three groups A (<130 mg/dL), B (130-179 mg/dL), and C (>180 mg/dL) based on FPG levels. A correlation was compared using Spearman's correlation. Box, whisker plots, and scatter plots were computed by R studio. Results After excluding those with missing values for either serum Cr, FPG, and HbA1c and sub-optimal renal function based on estimated glomerular filtration rate (eGFR) a total of 4,673 cases were analyzed. Subgroup A showed good glycemic control, whereas subgroup C showed poor glycemic control. The difference between eAG and FPG was significant (p < 0.0001). eAG values were found to be elevated than FPG values in groups A and B and almost the same in group C, whereas a moderately significant correlation with eAG and FPG in all three groups. Conclusion The correlation between eAG and FPG varies with blood glucose control and was significantly higher in the poorly controlled diabetes group. As the association between the FPG and eAG levels varies with the extent of blood glucose control, reporting eAG with HbA1c by a simple formula, at no additional cost will prove to be beneficial for clinical care.

HbA1c Performance in African Descent Populations in the United States With Normal Glucose Tolerance, Prediabetes, or Diabetes: A Scoping Review

Introduction

African descent populations in the United States have high rates of type 2 diabetes and are incorrectly represented as a single group. Current glycated hemoglobin A_1c (HbA_1c) cutoffs (5.7% to <6.5% for prediabetes; ≥6.5% for type 2 diabetes) may perform suboptimally in evaluating glycemic status among African descent groups. We conducted a scoping review of US-based evidence documenting HbA_1c performance to assess glycemic status among African American, Afro-Caribbean, and African people.

Methods

A PubMed, Scopus, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) search (January 2020) yielded 3,238 articles published from January 2000 through January 2020. After review of titles, abstracts, and full texts, 12 met our criteria. HbA_1c results were compared with other ethnic groups or validated against the oral glucose tolerance test (OGTT), fasting plasma glucose (FPG), or previous diagnosis. We classified study results by the risk of false positives and risk of false negatives in assessing glycemic status.

Results

In 5 studies of African American people, the HbA_1c test increased risk of false positives compared with White populations, regardless of glycemic status. Three studies of African Americans found that HbA_1c of 5.7% to less than 6.5% or HbA_1c of 6.5% or higher generally increased risk of overdiagnosis compared with OGTT or previous diagnosis. In one study of Afro-Caribbean people, HbA_1c of 6.5% or higher detected fewer type 2 diabetes cases because of a greater risk of false negatives. Compared with OGTT, HbA_1c tests in 4 studies of Africans found that HbA_1c of 5.7% to less than 6.5% or HbA_1c of 6.5% or higher leads to underdiagnosis.

Conclusion

HbA_1c criteria inadequately characterizes glycemic status among heterogeneous African descent populations. Research is needed to determine optimal HbA_1c cutoffs or other test strategies that account for risk profiles unique to African American, Afro-Caribbean, and African people living in the United States.

Influence of Fasting Glucose Levels on Achieving Glycemic Target in Individuals with Type 2 Diabetes: a Post Hoc Analysis

INTRODUCTION

FPG GOAL was a 24-week, open-label, treat-to-target randomized controlled trial which demonstrated that the optimal self-monitored fasting blood glucose (SM-FBG) target for most Chinese individuals with type 2 diabetes (T2D) using insulin glargine 100 IU/mL was 3.9-6.1 mmol/L. Individuals who achieved lower fasting plasma glucose (FPG) levels might achieve the target HbA1c of < 7% without increasing the risk of hypoglycemia.

METHODS

For this post hoc analysis, individuals were redivided into three groups based on their actual laboratory FPG levels at 24 weeks: level 1, ≤ 5.6 mmol/L; level 2, > 5.6 to ≤ 6.1 mmol/L; and level 3, > 6.1 to ≤ 7.0 mmol/L.

RESULTS

At week 24, 863 individuals with diabetes had available FPG data and 179, 122, and 179 individuals achieved FPG levels 1, 2, and 3, respectively. The proportion of individuals with HbA1c < 7% or HbA1c < 7% without hypoglycemia (≤ 3.9 or ≤ 3.0 mmol/L) was significantly higher in FPG levels 1 (p < 0.01) and 2 (p < 0.05) than in level 3. The least squares mean changes from baseline in HbA1c (- 1.77% and - 1.66% vs - 1.34%; both p < 0.001) and 2-h postprandial glucose (- 3.88 mmol/L and - 3.98 mmol/L vs - 3.22 mmol/L; both p < 0.05) were also significantly higher in FPG levels 1 and 2 compared with level 3. Linear regression analysis showed a moderate relationship between FPG and HbA1c levels at 24 weeks (r = 0.449).

CONCLUSIONS

Chinese individuals with T2D who achieved lower FPG levels with insulin glargine 100 IU/mL were more likely to achieve the recommended target HbA1c of < 7% compared with those with higher FPG levels. ClinicalTrials.gov identifier NCT02545842.

Glycaemic control in patients with type 2 diabetes initiating second-line therapy: Results from the global DISCOVER study programme

AIM

To assess glycaemic control and factors associated with poor glycaemic control at initiation of second-line therapy in the DISCOVER programme.

MATERIALS AND METHODS

DISCOVER (NCT02322762 and NCT02226822) comprises two similar prospective observational studies of 15 992 people with type 2 diabetes (T2D) initiating second-line glucose-lowering therapy in 38 countries across six regions (Africa, Americas, South-East Asia, Eastern Mediterranean, Europe and Western Pacific). Data were collected using a standardized case report form. Glycated haemoglobin (HbA1c) levels were measured according to standard clinical practice in each country, and factors associated with poor glycaemic control (HbA1c >8.0%) were evaluated using hierarchical regression models.

RESULTS

HbA1c levels were available for 80.9% of patients (across-region range [ARR] 57.5%-97.5%); 92.2% (ARR 59.2%-99.1%) of patients had either HbA1c or fasting plasma glucose levels available. The mean HbA1c was 8.3% (ARR 7.9%-8.7%). In total, 26.7% of patients had an HbA1c level ≥9.0%, with the highest proportions in South-East Asia (35.6%). Factors associated with having HbA1c >8.0% at initiation of second-line therapy included low education level, low country income, and longer time since T2D diagnosis.

CONCLUSIONS

The poor levels of glycaemic control at initiation of second-line therapy suggest that intensification of glucose-lowering treatment is delayed in many patients with T2D. In some countries, HbA1c levels are not routinely measured. These findings highlight an urgent need for interventions to improve monitoring and management of glycaemic control worldwide, particularly in lower-middle- and upper-middle-income countries.

Clinical inertia, reverse clinical inertia, and medication non-adherence in type 2 diabetes

PURPOSE

Clinical inertia and medication non-adherence are thought to contribute largely to the suboptimal glycemic control in many patients with type 2 diabetes. The present review explores the relations between A1C targets, clinical inertia and medication non-adherence in type 2 diabetes.

METHODS

We searched PubMed for English-language studies published from 2001 through June 1, 2018. We also manually searched the references of selected articles, reviews, meta-analyses, and practice guidelines. Selected articles were mutually agreed upon by the authors.

RESULTS

Clinical inertia is the failure of clinicians to initiate or intensify therapy when indicated, while medication non-adherence is the failure of patients to start or continue therapy that a clinician has recommended. Although clinical inertia may occur at all stages of diabetes treatment, the longest delays were reported for initiation or intensification of insulin. Medication non-adherence to antidiabetic drugs may range from 53 to 65% at 1 year and may be responsible for uncontrolled A1C in about 23% of cases. Reverse clinical inertia can be acknowledged as the failure to reduce or change therapy when no longer needed or indicated. Clinical inertia and medication non-adherence are difficult to address: clinician-and patient-targeted educational programs, more connected communications between clinicians and patients, the help of other health professional figures (nurse, pharmacist) have been explored with mixed results.

CONCLUSIONS

Both clinical inertia and medication non-adherence remain significant barriers to optimal glycemic targets in type 2 diabetes. Moreover, part of clinical inertia may be a way through which clinicians face current uncertainty in medicine, including some dissonance among therapeutic guidelines. Scientific associations should find an agreement about how to measure and report clinical inertia in clinical practice and should exhort clinicians to consider reverse clinical inertia as a cause of persisting inappropriate therapy in vulnerable patients.

Validity of hemoglobin A1c for diagnosing diabetes among people with and without HIV in Uganda

Sub-Saharan Africa (SSA) is facing a growing co-epidemic of chronic HIV infection and diabetes. Hemoglobin A1c (A1c) may underestimate glycemia among people living with HIV (PLWH). We estimated the validity of A1c to diagnose diabetes among PLWH and HIV-uninfected persons in rural Uganda. Data were derived from a cohort of PLWH and age- and gender-matched HIV-uninfected comparators. We compared A1c to fasting blood glucose (FBG) using Pearson correlations, regression models, and estimated the sensitivity and specificity of A1c for detecting diabetes with FBG ≥126 mg/dL as reference standard. Approximately half (48%) of the 212 participants were female, mean age of 51.7 years (SD = 7.0) at enrollment. All PLWH (n = 118) were on antiretroviral therapy for a median of 7.5 years with mean CD4 cell count of 442 cells/µL. Mean FBG (89.7 mg/dL) and A1c (5.6%) were not different between PLWH and HIV-uninfected ( P > 0.50) groups, but the HIV-uninfected group had a higher prevalence of A1c >5.7% (33% vs. 20%, P = 0.024). We found a relatively strong correlation between A1c and FBG (r = 0.67). An A1c ≥6.5% had a poor sensitivity (46%, 95% CI 26-67%) but high specificity (98%, 95% CI 96-99%) for detecting diabetes. More work is needed to define an optimal A1c for screening diabetes in SSA.

Is fasting plasma glucose in early pregnancy a better predictor of adverse obstetric outcomes than glycated haemoglobin?

OBJECTIVES

To determine, in a multi-ethnic cohort, the suitability of first-trimester fasting plasma glucose and HbA1c levels in non-diabetic range to identify women without diabetes at increased pregnancy risk.

STUDY DESIGN

A retrospective analysis of a prospective cohort between April 2013 and September 2015. Universal testing for fasting plasma glucose and HbA1c levels at the first antenatal blood sampling was performed and women were screened for gestational diabetes mellitus at 24-28 weeks' gestation. Primary outcomes were macrosomia and pre-eclampsia, and secondary outcomes preterm delivery, Caesarean section and large-for-gestational age. Different fasting plasma glucose and HbA1c cut-off levels were assessed for associations with outcomes.

RESULTS

1,228 pregnancies were included for outcome analysis. After adjustment for potential confounders, no association was found between fasting plasma glucose levels and pregnancy outcomes. Women with an HbA1c ≥5.8% (39.9 mmol/mol) showed an increased risk of macrosomia (OR 2.69, 95% CI 1.16-6.24); an HbA1c ≥5.9% (41 mmol/mol) threshold was independently associated with a three-fold risk of pre-eclampsia (95% CI 1.03-9.9) and an HbA1c ≥6.0% (42.1 mmol/mol) with a four-fold risk of large-for-gestational age (95% CI 1.49-11.07).

CONCLUSIONS

In a multi-ethnic population, first-trimester fasting plasma glucose levels were not a better predictor of pregnancy complications than HbA1c. Further, an early HbA1c ≥5.8% (39.9 mmol/mol) threshold is already associated with an increased risk of macrosomia.

Cause-specific risk of major adverse cardiovascular outcomes and hypoglycemic in patients with type 2 diabetes: a multicenter prospective cohort study

PURPOSE

Glycated hemoglobin A1_c (HbA1_c) and fasting plasma glucose (FPG) was identified to account for the risk of cardiovascular diseases in type 2 diabetic patients, but no study evaluated the risk based on both HbA1_c and FPG levels. We described the risk of major adverse cardiovascular events (MACE) and hypoglycemic in type 2 diabetic patients according to both HbA1_c and FPG levels.

METHODS

With the usage of databases of Action in Diabetes and Vascular disease: preterAx and diamicroN-MR Controlled Evaluation (ADVANCE), 1815 patients from 61 centers in China was identified and grouped according to the criterion value of HbA1_c and FPG: Good glycemic control (HbA1_c < 6.5%, FPG < 6.1 mmol/L); Insufficient glycemic control (HbA1_c < 6.5%, FPG ≥ 6.1 mmol/L or HbA1_c ≥ 6.5%, FPG < 6.1 mmol/L); Poor glycemic control (HbA1_c ≥ 6.5%, FPG ≥ 6.1 mmol/L). Time-varying multivariable Cox proportional hazards models were employed.

RESULTS

Average age was 64.8 ± 5.8 years, with a median of 4.8 years of follow-up. Overall, the incidence rates of MACE were 20.6 per 1000-person-years in Good glycemic control compared with 45.9 per 1000-person-years in Insufficient glycemic control (adjusted hazard ratio (aHR): 1.99; 95% CI 1.11-3.56; p = 0.02) and 54.7 per 1000-person-years in Poor glycemic control (aHR: 2.46; 95% CI 1.38-4.40; p = 0.002), respectively. The risk of hypoglycemic was highest in Insufficient glycemic control; 67.3 per 1000-person-years compared with 46.3 per 1000-person-years in Good glycemic control (aHR: 1.62; 95% CI 1.03-2.56; p = 0.04). Apart from this, we also observed that both MACE (aHR:1.41; 95% CI 1.13-1.77; p = 0.003) and hypoglycemic episodes (aHR: 1.82; 95% CI 1.48-2.24; p < 0.001) were sufficiently more frequent in the insulin-exposed group than the non-exposed group. In a post-hoc analysis, the risk of MACE (aHR:1.43; 95% CI 1.09-1.86; p = 0.01) and hypoglycemic (aHR: 1.99; 95% CI 1.46-2.69; p < 0.001) were more pronounced in Insufficient glycemic control with insulin exposure.

CONCLUSIONS

We observed a significant association of cause-specific risk of MACE and hypoglycemic with Insufficient glycemic control, particularly with insulin exposure.

Re-examining the sensitivity of HbA1c to screen for diabetes mellitus

BACKGROUND

One of the laboratory tests recommended by the American Diabetes Association (ADA) to screen for diabetes mellitus (DM) is HbA1c, and it is particularly suitable for segments of the population that cannot or are unwilling to fast for a screening test. The aim of this study was to determine whether HbA1c would be a useful tool to screen for DM in a real-world setting if ADA guidelines for repeat testing to confirm the diagnosis of DM are strictly adhered to.

METHODS

A retrospective database study was performed by extracting demographic and laboratory data from a chronic disease registry that collects data on adults from three tertiary hospitals and nine large primary care clinics in Singapore. Data were extracted and analyzed for adults not previously known to have DM whose data was captured in the registry between 2005 and 2016 with HbA1c and at least two diagnostic tests for DM (fasting plasma glucose or 2-h plasma glucose) performed within 4 weeks after HbA1c determination.

RESULTS

In all, 3928 adults were included in this study. The sensitivity, specificity, and area under the receiver operating characteristic curve for HbA1c at a threshold of 6.5% were 85.2%, 82.3%, and 0.914, respectively. A higher sensitivity was found in female adults, younger adults, and those of non-Chinese ethnicity.

CONCLUSIONS

The sensitivity of HbA1c as a screening test for DM in this study was significantly higher than that reported previously. This work provides additional evidence supporting the inclusion of HbA1c as one of the screening tests for DM.