Fatigue and tiredness in diabetes

Health care professionals know only too well what tiredness feels like. Many of our patients feel tired too – both from their health problems and from home or work pressures.

Fatigue has been defined as ‘an overwhelming, debilitating, and sustained sense of exhaustion that decreases one's ability to carry out daily activities, including the ability to work effectively and to function at one's usual level in family or social roles.’1

Tiredness is a frequent complaint of patients in primary care. Among people aged 18–65 years, 15.3% reported tiredness or feeling run down.2 Patients visiting Scottish GP practices were formally interviewed about their reason for attending and asked directly about other symptoms. Tiredness was reported by 25.6% of men and 42.9% of women aged ≤36 years; and by 33.9% of men and 66.3% of women aged >36 years.3

A systematic review and meta-analysis of studies reporting on differential diagnosis of fatigue in primary care included 26 studies. Heterogeneity made comparisons difficult. Three prospective studies with defined diagnostic standards found a prevalence of serious somatic diseases of 4.3% (CI 2.7–6.7%). Diabetes, anaemia and hypothyroidism were the most frequent diagnoses.4

Diabetes UK's 4Ts campaign to raise awareness of the symptoms of type 1 diabetes in children lists four warning signs: ‘toilet, thirsty, tired, and thinner’.5

‘[A] lot of us have more to contend with than “just” diabetes… I was absolutely knackered when diagnosed. Spent most of my days in bed, but getting no rest, fatigued to the point of (muscle) pain.’6

‘It was more than tiredness, though. It was a weariness so profound that I used to wake up dreading each day; a draining, dismal lethargy that smothered any glimmer of enjoyment in life.’ Teresa McLean's type 1 diabetes was diagnosed after travelling in Afghanistan. Later she said, ‘If I had to pick a word to describe what I feel like most of the time it would be tired. The little time I spend in the middle ground between hypo and hyper I spend feeling drained. And it is not normal, welcome tiredness – the sort you feel after a hard day's work – it is a different kind altogether, a hybrid of the draining exhaustion of hyperglycaemia and the destructive weariness of the beast [hypoglycaemia]… The tiredness I am talking about is feeling tired of living. In spirit I do not feel that at all and I definitely do not feel tired of life – but the fact remains that it always feels like three o'clock in the afternoon in my life.’7

A review identified 4259 papers about fatigue or vitality and diabetes. Ten were suitable for full review, among which three assessed fatigue as the primary endpoint. Prevalence of fatigue was between 23% to 40%. Various demographic, clinical, and personal factors were associated with fatigue, but with conflicting results.1

A Dutch study included in the three described above compared 214 randomly selected people with type 1 diabetes with age- and sex-matched controls; 66 had continuous glucose monitoring and symptom diaries. People with type 1 diabetes were much more likely to report fatigue (40% [95% CI 34–47%]) compared with controls (7% [3–10%]). ‘Age, depression, pain, sleeping problems, low self-efficacy concerning fatigue, and physical inactivity were significantly associated with chronic fatigue.’ Glucose control did not appear to have a major influence on fatigue although those with chronic fatigue had slightly less time in hypoglycaemia.8

Glycaemia

Fatigue is one of the symptoms of hypoglycaemia: as the glucose falls the person may get increasingly drowsy or confused, and eventually comatose. People experiencing nocturnal hypoglycaemia may not wake up (which may be dangerous, and also causes morning tiredness). Those who do wake can treat it, but lose sleep. Anxiety about night-time hypos keeps both the person with diabetes and family or carers awake, checking blood glucose.

Some hyperglycaemic people feel tired. Diabetic ketoacidosis may be associated with some impairment of consciousness but coma occurs only in about 10% of people.9

Conditions associated with diabetes

‘I am… constantly tired and sleepy forgetting what I'm doing forgetting what I am saying… it's a nightmare with work all I want to do is sleep all day and night…Just had a…blood test and its come up that I have underactive thyroid.’10

Consider other endocrinopathies such as overactive thyroid or steroid insufficiency. Also consider complications such as cardiovascular disease, renal impairment, and chronic or occult infection. Of course, people with diabetes can have any additional condition causing tiredness, such as anaemia – not all tiredness is ‘just’ diabetes.

An American case report describes a 43-year-old man with a six-month history of fatigue, decreased libido, and erectile dysfunction. He also had aching joints. He was found to have diabetes, but also hypogonadotrophic hypogonadism, abnormal liver function, and raised iron and ferritin levels. A diagnosis of haemochromatosis was confirmed.11

Obstructive sleep apnoea

‘A lorry driver suffering from sleep apnoea admitted nodding off at the wheel and causing a pile-up which killed a man… [He] ploughed into a queue of stationary traffic on the M62 motorway… nine vehicles were damaged…’ The lorry driver ‘told the inquest he had been to see his doctor four months before the accident, complaining of tiredness. The doctor did tests for diabetes, which came back negative, and it was not until after the crash that sleep apnoea was first considered.’12

A three-year study of 783 patients with suspected obstructive sleep apnoea or hypopnoea (OSAH) recorded 375 crashes, 252 in patients and 123 in sex- and age-matched controls. The increased risk of a motor vehicle collision (MVC) was confined to those with proven OSAH – people with normal polysomnography did not have an excessive risk. ‘Patients with OSAH are particularly prone to MVCs associated with personal injury, and this increased risk occurs even in patients with mild OSAH. Subjective daytime sleepiness does not appear to be particularly helpful in terms of risk prediction for MVC… MVCs associated with OSAH are potentially preventable.’13

Obstructive sleep apnoea is usually caused by a physical block to airflow, for example by relaxation of upper throat muscles, causing intermittent pauses in breathing while asleep. This is a key characteristic if observed. Other symptoms include excessive daytime sleepiness, with fatigue, and loss of energy.14

Obstructive sleep apnoea is more likely in men, in people over 40 years old, and in people who have a large neck (for example, collar size over 17 inches), are overweight (so have more fat in their neck, narrowing the pharyngeal airway), have high blood pressure, who smoke, drink excessive alcohol, and among people with diabetes.

Up to 40% of people with obstructive sleep apnoea have diabetes. Among people with type 2 diabetes, over 50% have obstructive sleep apnoea. However, obesity is a factor in both conditions. Obstructive sleep apnoea increases the risk of cardiovascular disease.15, 16 Have a high index of suspicion and seek specialist advice early.

‘You must tell DVLA if you have obstructive sleep apnoea which affects your ability to drive safely; obstructive sleep apnoea syndrome.’17

Treatment of obstructive sleep apnoea includes weight loss, stopping smoking and alcohol, and continuous positive airway pressure (CPAP) therapy while sleeping. Treatment with CPAP reduces motor vehicle crash rates.18

Diabetes self-care

Wearable technology brings great benefits to people with type 1 diabetes. New pump users are worried that they will roll onto the pump, perhaps pressing buttons, or pull the infusion set out. Most pumps can be locked and disconnection is rare. Flash glucose monitoring or continuous glucose monitoring devices may cause similar initial anxiety. Equipment alarms may disturb sleep. This is usually appropriate as action to treat hypoglycaemia could be required.

Narcolepsy

Narcolepsy is one of the most extreme versions of tiredness. It is estimated that it affects about 30,000 people in the UK.19 Affected people may fall asleep at any time, sometimes suddenly, and sometimes with cataplexy. People with narcolepsy are less likely to develop type 1 diabetes than the rest of the population. This is thought to be related to variants of the major histocompatibility complex class II molecule DQ0602 which appears to protect from type 1 diabetes but confers strong susceptibility to narcolepsy.20

Summary

Tiredness is a common among the population.

Tiredness is a common presenting symptom of diabetes.

People with established diabetes often feel fatigued. There are multiple reasons – including hypoglycaemic episodes, and hyperglycaemia, the effort of diabetes self-care, complications of diabetes, related conditions such as endocrinopathy, and infection.

Obstructive sleep apnoea is very common among people with type 2 diabetes. Exclude this in those with excessive daytime tiredness, especially if they have a large neck or are overweight. Failure to diagnose and treat obstructive sleep apnoea can have tragic, even fatal, consequences.

Remember that people with diabetes can have additional non-diabetes-related health problems. Tiredness is often not ‘just’ diabetes.