Antihypertensive and Lipid-Lowering Medication Adherence in Young Adults With Youth-Onset Type 2 Diabetes

Abstract

Importance: Youth-onset type 2 diabetes is associated with early development of chronic complications. Treatment of elevated blood pressure (BP), nephropathy, and dyslipidemia are critical to reduce morbidity. Data are needed on adherence to BP- and lipid-lowering medications in young adults with youth-onset diabetes.

Objective: To assess adherence and factors associated with adherence to BP- and lipid-lowering medications in young adults with youth-onset type 2 diabetes and diagnoses of hypertension, nephropathy, or dyslipidemia.

Design, setting, and participants: This cohort study measured medication adherence with 3 monthly unannounced pill counts at 2 time points 1 year apart during iCount, conducted during the last years (2017-2019) of the observational phase of the Treatment Options for Type 2 Diabetes in Adolescents and Youth study. Psychosocial factors associated with medication adherence were examined. Participants included individuals with youth-onset type 2 diabetes with hypertension, nephropathy, or dyslipidemia receiving diabetes care in their communities. Data were analyzed from September 2022 to September 2023.

Main outcomes and measures: The main outcome was BP- and lipid-lowering medication adherence, with low adherence defined as using less than 80% of pills and high adherence, at least 80% of pills. Psychosocial factors were measured using the Beliefs about Medicines Questionnaire and Material Needs Insecurities Survey.

Results: Of 381 participants in iCount, 243 participants (mean [SD] age, 26.12 [2.51] years; 159 [65.43%] women) with hypertension, nephropathy, or dyslipidemia were included in analysis. Among 196 participants with hypertension or nephropathy, 157 (80.1%) had low adherence. Participants with low adherence, compared with those with high adherence, were younger (mean [SD] age, 25.99 [2.41] vs 27.26 [2.41] years; P = .005), had higher glycated hemoglobin A1c (mean [SD], 10.33% [2.66 percentage points] vs 8.85% [2.39 percentage points]; P = .001), shorter diabetes duration (mean [SD], 12.32 [1.49] vs 12.90 [1.46] years; P = .03), and less education (eg, 17 participants [10.83%] vs 0 participants with no high school diploma; P = .004). Of 146 participants with dyslipidemia, 137 (93.8%) had low adherence and only 9 participants (6.2%) had high adherence. Of 103 participants with low adherence to BP-lowering medications and using oral hypoglycemic agents, 83 (80.58%) had low adherence to oral hypoglycemic agents. Beliefs that medications are necessary were higher for participants with high adherence to BP-lowering medications than those with low adherence in unadjusted analyses (mean [SD] necessity score, 16.87 [6.78] vs 13.89 [9.15]; P = .03). In adjusted multivariable analyses of participants with hypertension or nephropathy, having at least 1 unmet social need (odds ratio [OR], 0.20; 95% CI, 0.05-0.65; P = .04) and medication concerns (OR, 0.63; 95% CI, 0.40-0.96; P = .01) were associated with worse medication adherence 1 year follow-up. Diabetes distress, self-efficacy, depressive and anxiety symptoms, and self-management support were not associated with 1-year medication adherence.

Conclusions and relevance: These findings suggest that adherence to BP- and lipid-lowering medications was very poor in this cohort. To improve medication adherence and prevent early vascular events, approaches that identify and address medication concerns and unmet social needs are needed.

Figure 1.. Participant Enrollment

The iCount participants and all the participants originally enrolled in the TODAY randomized clinical trial did not differ at baseline by age, gender, race, ethnicity, body mass index, diabetes duration, or glycated hemoglobin A_1c.

Figure 2.. Oral Hypoglycemic Agent (OHA), Blood Pressure–Lowering, and Lipid-Lowering Medication Adherence in Participants With Hypertension, Nephropathy, or Dyslipidemia

Low adherence was defined as having used less than 80% of prescribed medication; high adherence, 80% or more of prescribed medication.