A prescription can only help if treatment can be continued in everyday life.
New research involving almost 80,000 people with type 2 diabetes suggests that long-term difficulty sticking with diabetes medicine is associated with a substantially higher risk of heart disease and stroke.
The study tracked medication patterns for as long as 10 years using Danish national health records. Instead of asking patients whether they remembered to take their medicine, researchers examined pharmacy records month by month to see how prescription use changed over time.
Type 2 diabetes is often thought of mainly as a blood sugar problem, but its effects reach far beyond glucose levels. Persistently high blood sugar can damage the lining of blood vessels and contribute to the processes that lead to narrowed arteries, heart attacks and strokes.
People with diabetes may also have other cardiovascular risks, including high blood pressure, abnormal cholesterol levels and excess weight. This is why preventing heart and blood vessel disease is a major goal of modern diabetes care.
Blood sugar-lowering medicines can help manage the disease, and some modern diabetes drugs can provide additional heart or kidney benefits in appropriate patients. Yet taking long-term treatment consistently can be difficult, especially when diabetes initially causes few obvious symptoms.
To study this problem, researchers from the University of Copenhagen and collaborating institutions examined 79,510 Danish adults. All had recently been diagnosed with type 2 diabetes and started a non-insulin glucose-lowering medicine between 2005 and 2012.
Over the following decade, the researchers identified three different medication patterns. Around 41% of participants consistently maintained high prescription adherence, while about one-third followed a moderate pattern.
The remaining 26% showed an early decline in adherence and then remained at a low level. This group experienced the poorest cardiovascular outcomes.
Compared with people in the consistently high group, those with persistently low adherence had a 27% higher rate of major cardiovascular events. Participants with moderate adherence had a smaller but still measurable 7% higher rate.
When the researchers looked at individual cardiovascular problems, the differences became even clearer. Low adherence was associated with a 45% higher rate of ischemic heart disease and a 24% higher rate of stroke.
Ischemic heart disease occurs when blood flow to the heart muscle is reduced, often because fatty deposits have narrowed the coronary arteries. It can cause chest pain and can eventually lead to a heart attack.
Perhaps the most concerning result involved younger adults. Among this group, low medication adherence was associated with a 73% higher rate of having a cardiovascular event before the age of 55 compared with people who consistently used their prescribed treatment.
Early-onset type 2 diabetes can be particularly serious because patients may spend a much larger portion of their lives exposed to high blood sugar and related metabolic problems. Preventing complications early could therefore have benefits that extend for decades.
The study also provides a reminder that medication adherence is not simply about personal discipline. People in the low-adherence group were more likely to live alone, have lower incomes and be managing additional chronic illnesses.
A person juggling several medicines, medical appointments, family responsibilities and financial pressure may face very different barriers from someone with fewer demands. Recognizing those barriers could help doctors provide practical support instead of simply repeating instructions.
The research team accounted for many social and health differences in its statistical analysis. Even after doing so, poorer medication adherence remained associated with higher cardiovascular risk.
Consistent users also gained time without serious cardiovascular disease. On average, they remained free of major heart and circulatory complications for more than seven additional months compared with people in the low-adherence group.
The research was published in The Lancet Regional Health – Europe. Associate Professor Jordi Merino of the Novo Nordisk Foundation Center for Basic Metabolic Research at the University of Copenhagen led the study, with Lise B. Nielsen as first author.
There are important limitations. Pharmacy records show whether medicine was supplied, not whether every tablet was swallowed, and an observational study cannot establish with certainty that medication adherence itself produced the difference in cardiovascular outcomes.
People who regularly fill prescriptions may also be more likely to exercise, attend medical appointments, eat healthier foods or follow other treatments. Although researchers can adjust for known differences, they cannot completely remove every possible influence.
Even so, the decade-long patterns are useful because they show that medication behavior can change early and remain different for years. That may give healthcare professionals an opportunity to identify people who are struggling soon after diagnosis rather than waiting until complications appear.
The study’s broader message is not that patients should simply be told to try harder. It suggests that doctors and health systems should ask why treatment is difficult, simplify plans where possible and provide support suited to each person’s circumstances.
For people with type 2 diabetes, the findings also underline the importance of discussing medication problems rather than quietly stopping treatment. Side effects, costs or other concerns can often be addressed, and any change to diabetes medicine should be made with a healthcare professional.
Overall, this large study strengthens the evidence that long-term treatment habits matter for more than blood sugar readings. Supporting people to stay with appropriate diabetes treatment may be one practical way to reduce heart disease and stroke, particularly for those diagnosed at a younger age.
If you care about diabetes, please read studies about diabetes and vitamin B12, and the right diet for people with type 2 diabetes.
For more health information, please see recent studies about how to eat smart with diabetes, and turmeric and vitamin D: a duo for blood pressure control in diabetic patients.
Source: University of Copenhagen
