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.

Which aspects of executive dysfunction influence ability to manage diabetes in older adults?

AIMS: To examine whether different aspects of executive function as measured by different assessment tools are associated with glycaemic control and other clinical characteristics in older adults with Type 2 diabetes. METHODS: We performed a cross-sectional study of older adults aged ≥ 70 years with Type 2 diabetes at a tertiary care diabetes centre. The Dysexecutive Questionnaire was used to measure self-reported executive dysfunction. Objective tests of executive functions included a modified clock drawing test (Clock-in-a-Box), Trail Making Tests (parts A and B) and verbal fluency. Demographic and clinical information was collected using questionnaires and surveys. Glycaemic control was measured by HbA(1c). RESULTS: We evaluated 145 patients [average age 77 ± 5 years, diabetes duration 15 ± 11 years, mean HbA(1c) 56 ± 11 mmol/mol (7.3 ± 1.1%)]. Poor performances on objective tests (low scores on Clock-in-a-Box and verbal fluency; and high scores on Trail Making Tests A and B) but not on the subjective test (the Dysexecutive Questionnaire), were associated with poor glycaemic control (r = -0.23, P < 0.005; r = -0.17, P < 0.04; r = 0.20, P < 0.01, r = 0.22, P < 0.008, r = -0.07, P < 0.42, respectively). In a multiple regression model (r(2) = 0.39), high Dysexecutive Questionnaire scores were associated with higher diabetes-related distress (P < 0.0004), depressive symptoms (P < 0.004), number of falls (P < 0.009), fear of falling (P < 0.01), less years of education (P < 0.0007) and fewer medications (P < 0.001). CONCLUSIONS: On the one hand, in older adults, executive dysfunction detected by objective tests is associated with poor glycaemic control and may be considered before prescribing complex treatment regimens. On the other hand, self-reported executive dysfunction is associated with risk and fear of falls, and more affective symptoms, which may indicate higher awareness of subtle deficits.

Hyperhomocysteinemia following a methionine load in patients with non-insulin-dependent diabetes mellitus and macrovascular disease.

In the setting of an outpatient diabetic clinic, we determined whether macrovascular disease in patients with diabetes mellitus is associated with hyperhomocysteinemia (elevated plasma homocysteine [H(e)] concentrations) following a methionine load. Methionine-load tests were performed in 18 healthy controls, 11 diabetics without vascular disease (five insulin-dependent [IDDM] and six non-insulin-dependent [NIDDM]); and 17 diabetics with vascular disease (five IDDM and 12 NIDDM). All subjects were male, and there was no significant difference in mean age among the three groups. We measured plasma H(e) concentrations before and 2, 4, 6, 8, and 24 hours after an oral methionine load. Hyperhomocysteinemia (peak plasma H(e) concentration > control mean +/- 2 SD) occurred with significantly greater frequency (seven of 18, 39%) in patients with NIDDM as compared with age-matched controls (7%), being more common in those with macrovascular disease (five of 12, 41%). The area under the curve (AUC) over 24 hours, reflecting the total period of exposure to H(e), was also elevated with greater frequency in patients with NIDDM and macrovascular disease (33%) as compared with controls (0%). We conclude that hyperhomocysteinemia is associated with macrovascular disease in a significant proportion of patients with NIDDM. Further investigation of this association may determine whether hyperhomocysteinemia contributes to the increased frequency and accelerated clinical course of vascular disease in patients with diabetes mellitus.

Hyperosmolar nonketotic diabetic syndrome following treatment of human immunodeficiency virus infection with didanosine.

OBJECTIVE: To determine whether didanosine (DDI), one of the drugs commonly used to treat infection with human immunodeficiency virus (HIV), contributes to the development of diabetes and hyperosmolar nonketotic diabetic syndrome (HNKDS). CASE SUMMARY: One female patient was treated with DDI for infection with HIV during pregnancy. Soon after starting DDI treatment, she developed diabetes, which progressed to HNKDS. CONCLUSIONS: Although not reported in the literature, hyperglycemia following treatment with DDI has been noted in 82 patients and is usually associated with pancreatitis. DDI should be recognized as one of the drugs known to potentially cause diabetes and HNKDS. With the increasing use of DDI and other drugs that cause hyperglycemia, such as pentamidine and dapsone, blood glucose should be monitored frequently in the HIV-infected patients.