A 65-year-old man comes to the clinic for follow-up treatment of hypertension. He is on 2 antihypertensive agents and says he is compliant with his medication regimen. The patient has no other medical problems. Blood pressure is 134/88 mm Hg and pulse is 78/min and regular. BMI is 32 kg/m². Physical examination is otherwise unremarkable. His fasting blood glucose levels on 2 recent laboratory workups were 108 mg/dL and 111 mg/dL. He is concerned about his risk of dementia because his father suffers from Alzheimer dementia.
Based on the study results, which of the following is the best response to this patient's concerns?

Question

Quizplus · Accepted Answer

Explanation: This study examined risk of dementia among cohort patients with and without diabetes. For each patient, glycemia measurements, obtained by various methods (eg, glucose levels, glycated hemoglobin levels), were transformed into average glucose levels calculated at baseline and over 5-year rolling windows (hence the average levels "over the preceding 5 years" in the table). With dementia as an outcome measure, hazard ratios (HRs), which are similar to relative risks but can be obtained at multiple time intervals, were obtained for different average glucose levels. A Cox regression model was used as it can take into account different time intervals. Among patients without diabetes, increases in average glucose levels-compared to a reference of 100 mg/dL (given HR = 1.00)-were associated overall with a statistically significant increased risk of dementia (p = 0.02). For average glucose levels of 105 and 110 mg/dL, the HRs were 1.11 and 1.14, respectively, representing increased risk of dementia (given HRs >1.00) with statistically significant confidence intervals (ie, they do not include the null value of 1.00 for HRs). Therefore, this patient may be at increased risk of dementia even with glucose levels of 108 mg/dL and 111 mg/dL. Among patients with diabetes, increases in average glucose levels-compared to a reference of 160 mg/dL (given HR = 1.00)-were also associated overall with a statistically significant increased risk of dementia (p = 0.003). Average glucose levels of 190 mg/dL were associated with an HR of 1.38. However, HRs for average levels of 170 mg/dL and 180 mg/dL did not reflect a statistically significant increase in risk of dementia as their corresponding confidence intervals included the null value. This suggests there is no dose-response relation as higher average glucose levels were not associated with proportionately higher risks of dementia (Choice A). (Choice B) There appears to be an increased risk of dementia not only among patients with uncontrolled diabetes. The p-values for the association between average glucose levels and dementia were statistically significant for patients both with and without diabetes. Among patients with diabetes, those who had uncontrolled diabetes with average glucose levels of 170 or 180 mg/dL did not have a statistically significant increase in risk of dementia. (Choice C) Because association does not imply causation, controlling glycemia may not help prevent dementia. (Choice D) A family history of dementia in a first-degree relative may increase the risk of developing Alzheimer dementia; however, based on the study results, diabetes may also be associated with increased risk. Educational objective: A p-value <0.05 reflects statistical significance.

A 65-Year-Old Man Comes to the Clinic for Follow-Up Treatment