QuestionSBA
QuestionChoice
This is a sulphonylurea. It is recommended that patients who are hyperglycaemic after commencing enteral feeding should be started on insulin
31890
c
Gliclazide
QuestionChoice
According to the Joint British Diabetes Societies guideline, insulin should be commenced in those with persistent hyperglycaemia who have recently started enteral feeding
31888
a
Insulin
QuestionChoice
This is a DPP-4 inhibitor. It is recommended that patients who are hyperglycaemic after commencing enteral feeding should be started on insulin
31891
d
Sitagliptin
QuestionChoice
This is a GLP-1 analogue. It is recommended that patients who are hyperglycaemic after commencing enteral feeding should be started on insulin
31892
e
Dulaglutide
QuestionChoice
This would be the first-line drug of choice in type 2 diabetes mellitus. However, as it would seem that the hyperglycaemia is a consequence of commencing enteral feeding, it is recommended that this patient is managed with insulin
31889
b
Metformin
Concept
Chapter
# Summary

Secondary causes of type 2 diabetes mellitus (T2DM) encompass a variety of conditions and factors that can induce or exacerbate hyperglycemia. These range from pancreatic and endocrine disorders to specific medications and glycogen storage diseases. It's important to consider these in patients with new-onset diabetes that presents atypically or doesn't respond to typical management.

# Definition

Secondary diabetes refers to forms of the disease where there is a clear causative factor aside from the typical insulin resistance or pancreatic β-cell failure associated with T2DM.

# Epidemiology

The prevalence of secondary diabetes varies based on the causative condition. While some causes such as pancreatic cancer are relatively common, others, like glycogen storage disorders, are quite rare.

# Aetiology

Secondary causes of T2DM include:

**Pancreatic Causes**

- Cystic fibrosis: An autosomal recessive disorder leading to mucus accumulation in various organs including the pancreas, resulting in fibrosis and loss of exocrine and endocrine function.
- Chronic pancreatitis: Long-standing inflammation of the pancreas can result in damage to islet cells, leading to diabetes.
- Haemochromatosis: Iron overload can lead to deposition in various organs including the pancreas, leading to diabetes.
- Cancer: Pancreatic neoplasms can destroy the islet cells, leading to diabetes.

**Endocrine Causes**

- Cushing's syndrome/disease: Elevated cortisol levels increase insulin resistance.
- Acromegaly: Excess growth hormone leads to insulin resistance.
- Pheochromocytoma: These rare adrenal tumors can induce diabetes through chronic catecholamine-induced glucose intolerance.
- Thyrotoxicosis: Thyroid hormone excess can enhance hepatic gluconeogenesis and glycogenolysis and impair insulin secretion.

**Drug Causes**

- Steroids: Chronic use can lead to glucose intolerance and diabetes due to increased insulin resistance.
- Atypical neuroleptics: These medications can lead to weight gain and increased insulin resistance.
- Thiazides: These diuretics may impair glucose tolerance, possibly by reducing insulin secretion.
- Beta-blockers: They can impair glycemic control through inhibition of insulin secretion and promoting insulin resistance.

**Glycogen Storage Disorders**

- Glycogen Storage Disease Type 1 (von Gierke's disease): The inability to perform gluconeogenesis can lead to hypoglycemia and secondary hyperglycemia.
- Glycogen Storage Disease Type 2 (Pompe disease): It affects the heart and skeletal muscles more than it causes diabetes, but can present with variable symptoms.

# Management

Management primarily involves addressing the underlying condition responsible for secondary diabetes. In cases where this is difficult/not possible, for example, pancreatic cancer, patients may require insulin therapy to manage hyperglycemia.



# NICE Guidelines

[NICE CKS on type 2 diabetes](https://cks.nice.org.uk/topics/diabetes-type-2/)
198
667
Secondary causes of diabetes
Topic
5
Endocrinology
6378
In patients with persistent hyperglycaemia following enteral feeding, insulin therapy is recommended to manage blood glucose levels effectively.
A 70-year-old patient is admitted to hospital with a stroke. During their hospital stay, they are started on enteral feeding via a nasogastric tube. They are persistently hyperglycaemic with their blood glucose monitoring as follows:


 - Monday AM: 14mmol/l
 - Monday PM: 13mmol/l
 - Tuesday AM: 15mmol/l
 - Tuesday PM: 16mmol/l
 (normal <6.1 mmol/l)

Their glucose levels were stable and consistently below 10mmol/l before enteral feeding was commenced. They have no past medical history of diabetes mellitus.


Which of the following is the best medication to start in this patient?
a