Type 1 Diabetes and Multimorbidity

Increasing numbers of patients experience two or more chronic health conditions at the same time.^1,2 Worldwide, the prevalence of multimorbidity in community settings has been estimated at 37.2%, with more than half of the global adult population over 60 years old reporting multimorbid conditions.³ Patients with autoimmune conditions such as type 1 diabetes (T1D) are no exception to the multimorbidity impact. In addition to risk of developing diabetes-related complications, studies suggest an increased prevalence of comorbidities among patients with T1D, including additional autoimmune diseases,⁴ cardiometabolic and musculoskeletal disorders,^5-7 and mental health conditions.⁸

As prevalence of T1D continues to increase among pediatric and adult populations,^9,10 what are the known connections between T1D and multimorbidity? How can the functional medicine approach help optimize health for these patients?

Type 1 Diabetes & Multimorbidity

Recent observational studies suggest that adult patients with T1D are often multimorbid. A 2022 cross-sectional retrospective study (n=6,967 German adult patients with T1D; mean age of 45 years; mean HbA1c of 7.9%) found that on average, each patient with T1D was diagnosed with 3.1 different disorders.⁵ This number was significantly higher compared to matched patients without diabetes, who had an average of 2.5 disorders. The most frequent disorder among patients with T1D was arterial hypertension (31.2%), followed by dyslipidemia (26.4%), dorsalgia (20.4%), diabetic neuropathy (17.3%), and depression (14.6%). Researchers reported that increased age had the strongest association with multimorbidity in this population, followed by higher HbA1c values. In addition, the mean number of disorders was slightly higher in female patients (3.6) than in male patients (3.0).⁵

Of interesting note, a 2023 meta-analysis of 38 studies found that compared to control groups, the prevalence of nearly every analyzed mental disorder was increased for patients with T1D.⁸ In this meta-analysis, depressive, anxiety, and eating disorders were the most examined.⁸ In addition, a large 2020 observational study investigated the impact of concomitant autoimmune diseases among patients with T1D and reported that among 179,248 people diagnosed with T1D, one in four (27%) had at least one coexisting autoimmune disease, with hypothyroidism, rheumatoid arthritis, and celiac disease being the most common.⁴ Investigators found that the risk of renal failure, ischemic stroke, and myocardial infarction significantly increased as the number of concomitant autoimmune diseases increased.⁴

Studies continue to investigate multimorbidity and T1D and how comorbidities can introduce additional health complications to these patients while also increasing the complexity of interventions.¹¹

Lifestyle-Based Adjunctive Treatments

Adjunctive lifestyle-based therapies such as nutrition and exercise have been highlighted as avenues for improving health in youth and adults with T1D, from increasing glycemic control to reducing premature mortality.^12-15 A 2020 meta-analysis of data from two multi-country cohorts and 42 additional clinical trials indicated that high-fiber intake (~35g/day) improved cardiometabolic health and reduced risk of premature mortality when compared to lower-fiber intake for adults who were diagnosed with prediabetes, type 2 diabetes, or T1D.¹³ Observational studies have also indicated that patients with T1D who follow a Mediterranean-style diet and/or a Dietary Approaches to Stop Hypertension (DASH) diet may help reduce future cardiovascular events related to their diabetes.¹⁶ In addition, a 2023 clinical trial (n=150 pediatric patients with T1D) reported that adherence to the Mediterranean diet significantly improved glycemic control,¹⁷ while a smaller clinical trial (n=20 pediatric patients with T1D) found that following a Mediterranean diet for six months improved blood glucose “time-in-range” from 52% of the time to 63%, reduced insulin dose from 0.76 u/kg to 0.72 u/kg, reduced diastolic blood pressure, and reduced LDL cholesterol from baseline measurements of 114 mg/dL to 104 mg/dL after treatment.¹⁸

Structured exercise programs that include resistance training have been shown to support glycemic control among patients with T1D.¹⁹ In addition, a small controlled clinical trial found that compared to no yoga, weekly yoga sessions as an adjunctive T1D therapy significantly lowered depression scores among adolescent girls with T1D.²⁰ In addition to implementing appropriate and personalized exercise programs, reducing sedentary behavior may also have a positive impact for adolescents and adults with T1D. A 2023 randomized controlled trial (n=32 inactive adults with T1D; mean age 28 years) found that when compared to uninterrupted sitting, interrupted sitting with three-minute bouts of light-intensity, self-paced walking at 30-minute intervals significantly reduced total mean glucose, increased glucose “time-in-range” by 13.7%, and reduced hyperglycemia by 15%.²¹

Conclusion

Patients with T1D have a high prevalence of multimorbidity and have increased risks of developing additional comorbidities that impact a range of physiological systems, from cardiovascular to musculoskeletal.^22-24 Lifestyle-based adjunctive interventions that include improving exercise habits, nutrition, and gut health as well as addressing potential toxicity, nutrient deficiency, and oxidative stress may be appropriate for a patient with T1D. Multi-faceted personalized treatment strategies are at the core of the functional medicine approach to health and wellness. At IFM’s upcoming Immune Advanced Practice Module (APM), learn more from functional medicine experts about autoimmune disorders and the clinical applications and lifestyle-based tools that help support immunity and health outcomes.