Shortfalls of the use of HbA1C-derived eAG in older adults with diabetes

AIMS

The hemoglobin HbA1C (HbA1C) value, translated into estimated average glucose concentration (eAG), is commonly used to assess glycaemic control and manage treatment regimens in people with diabetes. However, the relationships among HbA1C-derived eAG, and mean glucose concentration derived from continuous glucose monitoring (CGM) in different populations have not been well studied. We examined this relationship in older people with diabetes and compared the results to those currently used in clinical practice.

METHODS

Data from three studies evaluating CGM in older adults (≥70 years of age), with stable glycaemic control were analyzed retrospectively. Mean glucose and mean amplitude of glucose excursion (MAGE) were calculated from CGM data and correlated with HbA1C and HbA1C-derived eAG using the ADAG study formula.

RESULTS

HbA1C and CGM data were analyzed from 90 patients with mean age 76±5 years, HbA1C 7.9±1.2% (63±13 mmol/mol) and 77% with Type 2 diabetes. The HbA1C and HbA1C-derived eAG correlated significantly with CGM-measured mean glucose (r(2)=0.30, p<0.0001) and MAGE (r(2)=0.16, p=0.00013) in this population and all its subgroups, but the slopes of the relationship between HbA1C and eAG or CGM-measured mean glucose were significantly different.

CONCLUSIONS

HbA1C-derived eAG values may not accurately reflect CGM-measured mean glucose or MAGE in older adults with diabetes. Wide glucose excursions should be considered and HbA1C should be interpreted cautiously when making treatment changes based on HbA1C.

A national study on lipid management

BACKGROUND

Hyperlipidemia remains a major cause of morbidity in Western countries. The objective of this study was to document the percentage of adults who underwent periodical LDL measurement, and the percentage of patients with diabetes and post-angioplasty who were treated to goal.

METHODS

Using a national database, data were obtained on the percentage of adults who had an LDL performed and the percentage of adults with an LDL at pre-specified levels. We also assessed the attainment of target LDL levels in diabetic and post-angioplasty patients. Data were also collected from patients with an acute coronary syndrome (ACS) admitted to seven hospitals within a 5 year period (2000-2004).

RESULTS

Primary prevention: In 2005, 64.6% of the total population of 754,910 aged 35-44 had at least one record of LDL cholesterol measurement documented. This figure was 79.6% in the 717,617 adults aged 45-54. Secondary prevention: Of 253,233 diabetics in 2005, 220,023 (86.9%) have undergone at least one annual LDL measurement. The percentage of patients on statin therapy 3 and 12 months after an ACS admission increased significantly during the years 2000-2004 and reached 87%. Of the 42,292 patients who underwent PTCA during 2005, 34,346 (81.2%) have purchased at least 3 prescriptions of statins during 2005, 35,261 (83.4%) have performed at least one LDL measurement and 57.8% attained an LDL level of <100 mg/dl.

CONCLUSIONS

We have shown an improvement in primary and secondary preventions of CV disease as documented by LDL measured and attainment of treatment goals, but further efforts are needed.

Do patients with diabetes and low socioeconomic status receive less care and have worse outcomes? A national study

PURPOSE

The objective of the study was to assess the influence of socioeconomic status (SES) on the care of patients with diabetes.

METHODS

Quality indicators for patients who were taking medication for diabetes were established. Overall compliance with the quality indicators, as well as prevalence of diabetes by age, were obtained from a national database. Patients with national tax exemptions (used as a marker for low SES) were compared to those without.

RESULTS

Of 4,110,852 citizens aged 18-74, 210,988 (5.1%) were receiving medication for diabetes. The prevalence of diabetes reached 19.9% in people aged 65-74. 495,392 citizens had an exemption, and they had a higher prevalence of diabetes that those who did not (15.4% vs. 3.7%). Patients with an exemption had a higher rate of having a yearly HbA1c done, a yearly LDL level done, a yearly eye exam, a yearly urinary protein exam, of being treated with insulin for an elevated HbA1c than those without an exemption. In patients with an exemption there was a lower percentage with an HbA1c less than 7%, a higher percentage with an HbA1c greater than 9%, and a lower percentage with an LDL less than 130. Multivariate analysis showed that exemption status was a predictor of better performance on process measures (LDL test done, OR-1.03, 95% CI 1.01-1.06, HbA1c test done, OR 1.03, 95% CI- 1.01-1.05) and of worse outcomes (high LDL, OR 0.92, 95% CI, 0.90-0.95 and high HbA1c, OR, 0.85, 95% CI, 0.83-0.87).

CONCLUSIONS

In a country with universal healthcare, patients from a lower SES had an increased prevalence of diabetes and had greater adherence to preventive healthcare measures However, they were less successful in meeting target treatment goals.