Chronic Fatigue Common in Type 1 Diabetes

Miriam E. Tucker

August 20, 2013

Chronic fatigue is a common problem among people with type 1 diabetes, a new observational Dutch study finds.

The results were published online August 15 in Diabetes Care by Hans Knoop, PhD, a clinical psychologist who heads the Expert Center for Chronic Fatigue at Radboud University Nijmegen Medical Center, the Netherlands, and colleagues.

In the study, "chronic fatigue" was defined as severe fatigue lasting at least 6 months.

"The clinical message is that the prevalence of chronic fatigue is high in diabetes and is burdensome for patients. It is important to assess it, discuss it with patients, and, more important, to develop interventions. Our study indicates that behavioral interventions could be useful in the treatment of fatigue in diabetes, which we will determine in subsequent studies," Dr. Knoop told Medscape Medical News.

Surprisingly, chronic fatigue was not found to be closely associated with blood glucose levels and was not at all associated with acute fatigue (assessed by patient report on a visual scale at that moment). "Contrary to our hypothesis, we did not find a relationship between acute fatigue and glucose levels. Perhaps this can be explained by the fact that fatigue is multifactorially determined," he said.

This study investigated chronic fatigue as a symptom of type 1 diabetes and not "chronic fatigue syndrome," in which the fatigue is not associated with any known medical condition, Dr. Knoop clarified for Medscape Medical News.

Fatigue, Comorbidity, and Depression

A total of 214 randomly selected clinic patients aged 18 to 75 years with type 1 diabetes who were not severely ill or suffering from significant comorbidity were matched by age and sex with 214 population-based control subjects. All subjects completed the fatigue subscale of the Checklist Individual Strength (CIS), an 8-item test that assesses fatigue severity over the past 2 weeks. A score of 35 or higher indicates severe fatigue.

Other questionnaires were used to assess functional impairments, current health status, comorbidity, diabetes-related factors, and fatigue-related cognitions and behaviors, and HbA1c values and comorbidity were determined from medical records.

The type 1 diabetes subjects had a mean age of 48 years and diabetes duration of 29 years; 53% were female; and 16% had clinically relevant depressive symptoms, as assessed by the Beck Depression Inventory for Primary Care. Comorbidities were identified from the medical records in 24% and by patient self-report in 49%.

Chronic fatigue was present in 40% of the type 1 diabetes patients compared with just 7% of the matched controls, a significant difference. Fatigue severity was also significantly higher among the type 1 diabetes patients, with an average CIS score of 31 vs just 17 in the controls.

Diabetes patients with comorbidities (assessed from medical records) or clinically relevant depressive symptoms were significantly more likely to be chronically fatigued than those without comorbidities (55% vs 36%, P = .014) or without clinically relevant depressive symptoms (88% vs 31%, P < .001).

Patients who reported having neuropathy, nephropathy, or cardiovascular disease as complications of diabetes were also more likely to be chronically fatigued. Chronically fatigued type 1 diabetes patients were significantly more impaired compared with the other diabetes patients on all aspects of daily function, Dr. Knoop and colleagues note.

Significant predictors of chronic fatigue were younger age, clinically relevant depressive symptoms, more pain and sleeping problems, and a lower level of self-reported physical activity and self-efficacy concerning fatigue.

In a substudy of 66 type 1 diabetes patients who wore continuous glucose monitors for 5 days, the 25 who were chronically fatigued spent less time in hypoglycemia compared with 41 patients who were not chronically fatigued, but there were no significant differences between the 2 groups in mean glucose, glycemic variability or time spent in hyperglycemia. Acute fatigue was also not associated with any of the 4 glucose parameters.

Why the Fatigue, if Not Blood Sugar?

The significant relationship of fatigue with cognitive-behavioral variables and weak association with blood glucose levels suggest that behavioral interventions might help chronic fatigue in type 1 diabetes, the authors write.

Dr. Knoop told Medscape Medical News, "We think that the diabetes itself and its [medical] consequences can trigger fatigue. Once the fatigue is triggered, other factors step in and can perpetuate the symptom. Examples of these factors are sleep problems or a lowered level of activity."

He acknowledged that, because the study was cross-sectional, it was impossible to determine causation. "It is not possible to state with certainty what is cause and effect. However, we think it is likely that diabetes and its consequences [including treatment] trigger acute fatigue. In becoming chronic, factors like a low level of self-reported activity play an important role. Patients can get into a vicious circle, in which fatigue leads to a lowered activity level and a disrupted sleep-wake pattern, which also perpetuates the fatigue."

And, Dr. Knoop added, "Depression can cause fatigue, but…being fatigued can also lead to (often mild) depressive symptoms. More severe depression can lead to fatigue, and once the depression is treated, fatigue levels often normalize."

The authors have reported no relevant financial relationships.

Diabetes Care. Published online August 15, 2013. Abstract


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