Diabetes

Hypoglycaemia

Hypoglycaemia is uncommon in people without diabetes but relatively frequent in people with diabetes, mainly due to insulin therapy, and less frequently to use of oral anti-diabetic secretagogues such as sulphonylurea drugs, and rarely with other antidiabetic drugs.





In people with diabetes, hypoglycaemia is defined as a blood glucose of less than 3.9 mmol/L (70 mg/dL).
When hypoglycaemia develops in non­diabetic people, it is called spontaneous hypoglycaemia

If blood glucose falls, three primary physiological defence mechanisms operate:

• Endogenous insulin release from pancreatic β cells is suppressed
• Release of glucagon from pancreatic α cells is increased
• The autonomic nervous system is activated, with release of catecholamines both systemically and within the tissues.







In addition, stress hormones, such as cortisol and growth hormone, are increased in the blood. These actions reduce whole­body glucose uptake and increase hepatic glucose production, maintaining a glucose supply to the brain.

Most common symptoms of hypoglycaemia

Autonomic
• Sweating
• Trembling
• Pounding heart
• Hunger
• Anxiety

Neuroglycopenic

• Delirium
• Drowsiness
• Speech difficulty
• Inability to concentrate
• Incoordination
• Irritability, anger

Non-specific

• Nausea
• Tiredness
• Headache

Risk factors for hypoglycemia

strict glycemic control
• Long-duration of type 1 diabetes
• Duration of insulin therapy in type 2 diabetes
• Lipohypertrophy at injection sites causing variable insulin absorption
• Severe hepatic dysfunction
• Impaired renal function
• Unrecognized other endocrine disorder, e.g. Addison’s disease

• Gastroparesis due to autonomic neuropathy causing variable carbohydrate absorption

• Malabsorption, e.g. coeliac disease

Lifestyle issues

• Exercise
• Irregular lifestyle
• Increasing age
• Alcohol
• Early pregnancy
• Breast feeding
• No or inadequate glucose monitoring






Nocturnal hypoglycaemia in patients with type 1 diabetes is common but often undetected, as hypoglycaemia does not usually waken a person from sleep.
Patients may describe poor quality of sleep, morning headaches and vivid dreams or nightmares, or a partner may observe profuse sweating, restlessness, twitching or even seizures. The only reliable way to identify this problem is to measure blood glucose during the night.

Awareness of hypoglycaemia

For most individuals, the glucose level (threshold) at which they first become aware of hypoglycaemia is not constant but varies according to the circumstances in which hypoglycaemia arises (e.g. during the night or during exercise).
In addition, with longer duration of disease, and particularly in response to frequent hypoglycaemia, the threshold for generation of symptom responses to hypoglycaemia shifts to a lower glucose concentration.





Taken together, this means that individuals with type 1 diabetes may have reduced (impaired) awareness of hypoglycaemia.





Symptoms can be experienced less intensely, or even be absent, despite blood glucose concentrations below 3.0 mmol/L (55 mg/dL). Such individuals are at an especially high risk of severe hypoglycaemia. The prevalence of impaired awareness of hypoglycaemia increases with time; overall, it affects around 20–25% of people with type 1 diabetes and under 10% with insulin­ treated type 2 DM

Management of hypoglycemia

Acute treatment of hypoglycaemia
Treatment of hypoglycaemia depends on its severity and on whether the patient is conscious and able to swallow.





It is recommended that all glucose levels < 4.0 mmol/L (72 mg/dL) are treated. People with diabetes who recognise developing hypoglycaemia and able to swallow are encouraged to treat immediately. Options available include:





1- Oral fast-acting carbohydrate (15 g) is taken as glucose drink or tablets, e.g. 5 Dextrosol tablets (or 4 Glucotabs),150 mL pure fruit juice, 4 teaspoons of sugar dissolved in water)
2- Repeat capillary glucose measurement 1–15 mins later. If still < 4.0 mmol/L, repeat above treatment





3- If blood glucose remains < 4.0 mmol/L after three cycles (30–45 mins), consider glucagon 1 mg IM or 200 mL 10% glucose over 15 mins IV.
4- Once blood glucose is > 4.0 mmol/L, take additional long-acting carbohydrate of choice ex. Pieces of breads or biscuits

Severe (external help required)

This means individuals are either unconscious or unable to treat hypoglycaemia themselves. Treatment is usually by a relative or by paramedical or medical staff.

If patient is semiconscious or unconscious, parenteral treatment is required:

IV 100 mL 20% dextrose over 15 mins
Or
IV 200 mL 10% dextrose over 15 mins
Or
IM glucagon (1 mg)