HbA1c and Age in Non-Diabetic Subjects: An Ignored Association?

Impact of Anaemia on HbA1c Interpretation Among Normogylcaemic Individuals With Diabetes Mellitus: A Clinical Laboratory Observational Study

BACKGROUND AND AIM

Over the past decades, glycosylated haemoglobin (HbA1c) has been a gold standard for monitoring diabetes control over a long period, relative to blood glucose level (BGL) which measures short-term results. It is speculated that anaemia and factors that induce haemolysis may cause falsely elevated HbA1c leading to 'false positive' interpretations. This study aimed to investigate how anaemia impacts HbA1c.

METHODS

This was a pathology-based observational pilot study using archived data of diabetic subjects monitored with both BGL and HbA1c in regional New South Wales (NSW), Australia. A total of 28,487 cases of blood glucose results were pooled and those with HbA1c and anaemia results were evaluated for correlation with the BGL results. Data collection was limited to de-identified information from the laboratory information system, hence details on the ethnicity and medical history were unavailable. Descriptive frequencies and Pearson correlations were performed.

RESULTS

In the pooled data, 53.36% of individuals were females, and 50.54% had BGL ≥5.6 mmol/L. In the pilot dataset, the majority (64.86%) were males, 18.92% with BGL ≤5.6 mmol/L and 67.57% had HbA1c (≥6.5%). In the entire dataset, BGL was moderately and positively correlated with HbA1c (r = 0.6), whereas in the subset of individuals with normo-BGL and anaemia, the correlation was negative (r = -0.2).

DISCUSSION

This pilot investigation observed a pertinent issue, which is a negative correlation between glycaemia and HbA1c in patients with anaemia. HbA1c was falsely increased despite normal blood glucose levels in individuals with anaemia. This advances the speculation that anaemia falsely increases HbA1c. Therefore, caution is necessary while interpreting HbA1c results for patients with anaemia, and new methods for interpretation are required.

Shared Decision Making, Diagnostic Evaluation, and Pharmacotherapy in Type 2 Diabetes

BACKGROUND

Type 2 diabetes is one of the most important widespread diseases worldwide. In Germany, nearly one in five persons over age 65 has type 2 diabetes. The German National Disease Management Guideline for Type 2 Diabetes (NDMG; in German: Nationale Versorgungsleitlinie, NVL) contains updated recommendations for the diagnostic evaluation and pharmacotherapy of this disease as well as information about specific groups of people for whom early detection may be useful.

METHODS

The guideline has been updated, chapter by chapter, since 2018. Its recommendations are based on systematically searched and evaluated scientific evidence, the clinical expertise of a multidisciplinary panel of experts, and patient perspectives.

RESULTS

The new chapter on shared decision making includes a description of a structured approach that can be used when individual treatment goals have not been achieved. The diagnosis of diabetes newly requires at least two abnormally elevated laboratory values: e.g., fasting plasma glucose ≥ 126 mg/dL (≥ 7.0 mmol/L), HbA1c ≥ 6.5 % (≥ 48 mmol/mol) and/or casual plasma glucose ≥ 200 mg/dL (≥ 11.1 mmol/L). Cardiovascular and renal risks are to be considered in the choice of drug. Studies have shown that, in persons with cardiovascular disease, treatment with GLP-1 receptor agonists (GLP-1, glucagon-like peptide-1) or SGLT2 inhibitors (SGLT2, sodium-glucose co-transporter-2) was less likely than the comparison intervention to lead to certain patient-relevant endpoints, including all-cause mortality (OR = 0.88 and 0.84, respectively), hospitalization for heart failure (SGLT2 inhibitors: OR = 0.65), and worsening of renal function (OR = 0.61 and 0.59, respectively).

CONCLUSION

Current evidence continues to support the recommendations on pharmacotherapy of the 2021 guideline. The Guideline Group did not find evidence of adequate certainty to inform recommendations about the screening of persons at risk, HbA1c target values, or screening for sequelae and comorbidities. Better evidence on these matters would be desirable.

Naturally Occurring Endocrine Disorders in Non-Human Primates: A Comprehensive Review

Literature concerning veterinary medicine of non-human primates is continuously updated, yet endocrine disorders remain underreported. While case or survey reports of individual endocrinopathies are available, a comprehensive review is not. An exhaustive literature search on this subject via widely used academic search systems, (e.g., Google Scholar, PubMed, BioOne complete and Web of Science), and peer-reviewed publications, proceedings, and newsletters was performed. Selected major endocrine entities will be described with emphasis on clinical signs, morphologic appearances, concomitant diseases, as well as available treatment options. Mostly, no clinical signs were noted and on gross pathology, the endocrine organs were unremarkable. An endocrine-related diagnosis was frequently made as an incidental finding after standard histopathological examination. During the review, the pancreas represented the most affected endocrine organ and diabetes mellitus represented the most clinically significant disorder. Currently, no standard procedure for diagnosing, monitoring, or treating endocrine disorders in non-human primates exists.

Retrospective Evaluation of a Minor Dietary Change in Non-Diabetic Group-Housed Long-Tailed Macaques (Macaca fascicularis)

Macaques in captivity are prone to becoming overweight and obese, which may cause several health problems. A diet that mimics the natural diet of macaques may prevent these problems and improve animal welfare. Adjusting captive diets towards a more natural composition may include increasing fiber content and lowering the glycemic index, i.e., reducing the impact on blood glucose levels. Such a dietary change was implemented in our long-tailed macaque (Macaca fascicularis) breeding colony. The basic diet of monkey chow pellets remained the same, while the supplementary provisioning of bread was replaced by grains and vegetables. This study is a retrospective evaluation, based on electronic health records, that investigated whether this minor dietary change had a beneficial effect on relative adiposity and overweight-related health parameters in 44 non-diabetic, group-housed, female long-tailed macaques. Relative adiposity was measured with a weight-for-height index and blood samples were collected during yearly health checks. Glycemic response and lipid metabolism were evaluated using several biochemical parameters. Relative adiposity and overweight status did not differ after dietary change. Yet, relatively heavy individuals generally lost body weight, while relatively lean individuals gained body weight, leading to a more balanced body weight dynamic. Dietary change did not affect HbA1c and triglyceride levels, while fructosamine and cholesterol levels were significantly reduced. Thus, the minor dietary change had no significant effect on overweight status, but some biochemical parameters related to the risk of diabetes and cardiovascular disease were positively affected. This study emphasizes the importance of evaluating husbandry changes and that critically reviewing husbandry practices can provide valuable insights to improve animal health and welfare.

Hemoglobin A1c Levels Associated with Age and Gender in Taiwanese Adults without Prior Diagnosis with Diabetes

Several studies have reported that Hemoglobin A1c (HbA1c) levels increase with age for people without diabetes. However, HbA1c levels associated with age and gender have not been well investigated for Taiwanese adults. The objective of this study was to investigate the sex-specific association between HbA1c levels and age for Taiwanese adults without diabetes. The data were collected from the Taiwan Biobank database with inclusive criteria being participants without diabetes. The association between HbA1c values and age was conducted by linear regression analysis, HbA1c values between sexes were compared by two-sample t-test, and HbA1c levels among age groups were compared using one-way ANOVA. The results showed that HbA1c levels were positively correlated with age, and the levels for males were significantly higher than for females among all participants. However, there was no significantly positive correlation between HbA1c levels and age in males for age group of 50–70 years. The levels of males were significantly higher than females for age groups of 30–39 and 40–49 years. There were significant differences in HbA1c levels among age groups for all participants, males, and females except for the two age groups of 50–59 and 60–70 years in males. Age and gender were important factors affecting HbA1c levels. Our results suggested that the HbA1c cut-point levels for the diagnosis of diabetes should vary by age and gender.

Prevalence of prediabetes and type 2 diabetes in two non-random populations aged 44-77 years in the Faroe Islands

AIMS

The prevalence of type 2 diabetes is increasing worldwide but little known about the status in the Faroe Islands. The aim was therefore to determine the prevalence of type 2 diabetes mellitus and prediabetes in two non-random populations aged 44-77 years.

METHODS

This cross-sectional survey was conducted between 2011 and 2012 and included two sub-populations, namely 518 Septuagenarians aged 74-77 years (84% of the invited) and 401 Mark aged 44-73 years (87% of the invited). Subjects were screened for glycosylated haemoglobin, type A1c, non-fasting random plasma glucose, fasting plasma glucose followed by an oral glucose tolerance test. The screening was based on a diagnostic algorithm that included screening, diagnostic and confirmatory steps.

RESULTS

Each group was analysed separately. In the Septuagenarian group 20.4% had type 2 diabetes, with 5.2% being newly detected and a total of 59% had prediabetes. In the Mark group 4.1% had diabetes, with 2.1% being newly detected and 22.3% had prediabetes. Diabetes increased with age and was significantly more prevalent among men. Women had lower mean fasting plasma glucose concentrations and men had lower values for 2-hours plasma glucose. Significant predictors associated with diabetes mellitus included obesity (BMI ≥ 30, abnormal waist/hip ratio and vegetable consumption.

CONCLUSIONS

Among the Faroese populations studied, the prevalence of type 2 diabetes increased with age and was more prevalent among men. The detected prevalence was comparable to other Nordic countries for all age-groups.

Preventing misdiagnosis of diabetes in the elderly: age-dependent HbA1c reference intervals derived from two population-based study cohorts

BACKGROUND

Measurement of gylcated hemoglobin A1c (HbA1c) plays a central role in monitoring quality of antidiabetic therapy and in the diagnosis of diabetes. Several studies report increased levels of HbA1c in nondiabetic elderly. However, this observation did not reach incorporation into daily clinical practice or the respective guidelines. The present study aimed to evaluate HbA1c levels in relation to age in two independent population-based cohorts and to derive age-specific reference intervals.

METHODS

Four thousand two hundred sixty three participants from the Study of Health in Pomerania (SHIP-0) and 4402 participants from the independent study SHIP-Trend were included. HbA1c was determined by means of high-performance liquid chromatography. Multivariable linear regression models were performed. Reference intervals for HbA1c were determined.

RESULTS

Reference intervals were derived from a healthy subpopulation with the upper reference limit (URL) for HbA1c of 42.1 mmol/Mol (6.0%) for individuals aged 20-39 years increasing to 43.2 mmol/Mol (6.1%) for individuals aged 40-59 years. For people aged ≥60 years the URL was 47.5 mmol/Mol (6.5%). In both study populations an increase in HbA1c with age was observed. ANOVA revealed up to 8.5 mmol/Mol (0.77%) or 7.3 mmol/Mol (0.68%) higher estimated mean levels of HbA1c in the oldest compared to the youngest age group in SHIP-0 or SHIP-trend, respectively. Linear regression analyses confirmed the positive associations of HbA1c with age which was independent of BMI CONCLUSION: The present study confirmed the previously observed increase of HbA1c with increasing age in non-diabetic individuals. As a consequence age-dependent reference values for HbA1c were derived from two large and well defined reference populations. Implementation of them into daily practice may improve patient care and diagnosis of diabetes and reduce the risk of misdiagnosis and subsequent overtreatment of diabetes in elderly patients.

A Retrospective Time Trend Study Of Diabetes Overtreatment In Geriatric Patients

PURPOSE

We assessed changes in diabetes mellitus (DM) overtreatment prevalence in geriatric patients that had taken place after the introduction of the rule of therapy individualization in the Polish diabetes treatment guidelines.

PATIENTS AND METHODS

This time-trend assessment comprised two retrospective cross-sectional cohort studies of type 2 DM patients admitted to a geriatric ward in 2009-2010 (1st round) and in 2014-2015 (2nd round). A high-risk group was defined as patients on antihyperglycemic medications prior to admission, who were 80+ years old, diagnosed with dementia, end-stage renal disease, or had a history of macrovascular complications. The primary outcome measure was glycosylated A_1C hemoglobin (HbA_1C) ≤7.0% (53 mmol/mol).

RESULTS

213 patients in the 1st round and 83 in the 2nd round were included. Groups did not differ in age, gender, health and functional characteristics. The percentage of dementia (36.1% versus 18.8%, P=0.002) and of the high-risk cases (79.3% versus 67.7%, P=0.05) was higher in the 2nd round of the study. During the study, tight glycemic control prevalence in the high-risk group decreased significantly from 73.1% to 58.5%, P=0.04 (odds ratio 0.68, 95% CI 0.47-0.97), and the median value of HbA_1c increased significantly from 6.4%, IQR 5.7-7.3 (46 mmol/mol, IQR 39-56) to 6.7%, IQR 6.1-7.9 (50 mmol/mol, IQR 43-63), P=0.03.

CONCLUSION

Despite the principle of individualization of DM therapy that was in force, after a five-year observation, the problem of DM overtreatment still concerned a large percentage of geriatric patients, although a positive trend was noted in this respect.