Diabetes Mellitus and its Importance in Medicolegal Practice

By Dr. Paul E Jennings, Consultant Physician in Diabetes & Endocrinology

As a Physician and Endocrinologist with 20 years experience providing medical reports on clinical negligence matters, I’ve observed an increasing number of claims concerning the management of diabetes. These claims often fall into several key categories:

  • Delayed Diagnosis: Failure to diagnose diabetes early can lead to severe complications, particularly vascular issues, and reduced life expectancy.

  • Medication-Induced Diabetes: Accident, injury, or prolonged and inappropriate use of medications, especially steroids, that cause weight gain and subsequently lead to the development of Type 2 diabetes.

  • Diabetic Foot Ulcers: Delayed or inadequate treatment can lead to amputations, a common ground for negligence claims.

  • Gestational Diabetes: Failure to diagnose Gestational Diabetes or manage diabetes in pregnancy correctly such that the baby is harmed by uncontrolled blood glucose levels causing trauma to the child at birth resulting in cerebral palsy and other life changing conditions.

  • Hospital Errors: Incorrect prescriptions and failure to adjust insulin regimes can cause hyperglycaemic coma, hypoglycaemia, and death.

  • Unexpected Actions: Hypoglycaemia occurring that the claimant is unaware of that leads to uncharacteristic and inappropriate behaviour that can lead to abuse, violence and accidents.

  • Surgical Complications: Where the pancreas becomes damaged or is removed which leads to digestion problems, insulin dependent diabetes and malabsorption (Diabetes Type 3c).

It is therefore against this background that Diabetes mellitus and its importance in the setting of a potential medical negligence claim should be appreciated.

Diabetes is often not considered to be relevant due in part to a limited appreciation of the complexities of a group of metabolic disorders characterized by high blood sugar (glucose) levels that are often simply referred to as Diabetes.

Diabetes generally refers to medical conditions where high blood glucose levels over a prolonged period occur when the pancreas either does not produce enough insulin or when the body cannot effectively use the insulin it produces (called Insulin resistance).

Insulin is a hormone produced by the pancreas that regulates blood glucose levels by transferring glucose from the bloodstream into cells that use glucose as an energy source.

Excess glucose in the blood stream that cannot be used is excreted in the urine.

The main symptoms of diabetes include increased thirst, frequent urination, unexplained weight loss, fatigue, blurred vision, and slow healing of wounds.

Excess glucose remaining in the blood stream is toxic damaging the lining of blood vessels so If left untreated, diabetes can lead to serious complications such as cardiovascular disease, kidney failure, nerve damage, and vision loss all of which leads to premature death.

Increasing Prevalence and Implications

The rise in diabetes cases is mirrored by a growing number of medico-legal cases. Approximately 4.9 million people in the UK have diabetes, with around 1 million undiagnosed cases. High-risk groups include individuals from South Asian, Black African, and African-Caribbean backgrounds, often due to lifestyle factors. In hospitals, diabetes prevalence can reach 20%, leading to longer stays and poorer outcomes, thereby increasing litigation risks.

Diagnostic Criteria and Importance in Legal Context

Diagnosis is based on WHO and NICE guidelines and in the UK focuses on fasting blood glucose, Glucose Tolerance Test, and HbA1c levels.

HbA1c, also known as glycated haemoglobin, is a crucial marker used in the management and diagnosis of diabetes and refers to haemoglobin molecules that have glucose attached to them.

Haemoglobin is a protein found in red blood cells that carries oxygen from the lungs to the rest of the body for 2-3 months. When glucose in the bloodstream attaches to haemoglobin, it forms HbA1c. For individuals without diabetes, HbA1c levels are usually below 5.7% (41mmol/mol).

In people with diabetes, higher levels of HbA1c indicate poorer blood glucose control over the preceding 2-3 months. HbA1c is important because it provides an indication of average blood glucose levels over time. This makes it a valuable tool for assessing overall diabetes management and risk of complications as the higher the value and the longer it remains high the greater the risk of complications particularly complications involving vascular disease.

This measure is very useful in medico-legal practice as it provides information as to whether a complication such as an amputation is solely due to a period of negligent clinical care or was inevitable due to prolonged poor self-care.

The Types of Diabetes Mellitus:

  • Type 1 Diabetes: An autoimmune condition requiring lifelong insulin therapy.
  • Type 2 Diabetes: Often linked to lifestyle factors; it represents the majority of cases.
  • Gestational Diabetes: Occurs during pregnancy and increases the risk of Type 2 diabetes later.
  • Other Specific Types: Includes monogenic and secondary diabetes (e.g., due to pancreatitis or steroids).

Implications of Having Diabetes

  1. Health Impact – Poor diabetes management can lead to serious health issues such as heart disease, stroke, kidney failure, blindness, and nerve damage. These complications often form the basis of negligence claims due to the severe consequences of inadequate care.
  2. Employment Restrictions – Diabetes can impose restrictions on certain jobs, particularly those involving safety-sensitive tasks. Employment constraints related to diabetes management and potential hypoglycemia incidents are frequently examined in medico-legal cases.
  3. Monitoring and Management – Effective diabetes management requires rigorous blood glucose monitoring and maintaining HbA1c levels. Regular testing is crucial in optimizing treatment and minimizing complications, providing essential evidence in medico-legal evaluations of care quality.

Diabetes Complications

Poorly controlled diabetes can have serious and potentially life-threatening health consequences. When blood glucose levels are consistently elevated or fluctuate dramatically, it can lead to various complications affecting multiple organ systems in the body. The frequency at which patients with diabetes develop complications can vary widely depending on several factors, including the type of diabetes, duration of the condition, level of blood glucose control, presence of other health conditions, lifestyle factors, and access to healthcare.

Cardiovascular and Peripheral Vascular Complications ~ Diabetes accelerates damage to the major blood vessels by promoting atherosclerosis, thrombosis and vascular occlusion leading to increased heart disease, stroke and lower limb loss.  This process is also greatly increased by associated high blood pressure, high cholesterol or smoking.

Microvascular Complications ~ Microvascular complications, such as diabetic retinopathy, nephropathy, and neuropathy, are particularly relevant in medico-legal cases due to their severe impact on a patient’s health. Diabetic retinopathy, for example, can lead to significant vision impairment or blindness, while diabetic nephropathy can result in chronic kidney disease and require dialysis. Diabetic neuropathy can cause debilitating pain and loss of sensation, especially in the extremities.

Foot Problems ~ Diabetic foot complications, including ulcers and infections, are a frequent cause of negligence claims. These complications can rapidly escalate, leading to amputations if not promptly and adequately treated. The multidisciplinary care required to manage diabetic foot issues often falls short, resulting in serious, avoidable outcomes and subsequent litigation.

Metabolic Emergencies ~ Episodes of diabetic ketoacidosis (DKA) and severe hypoglycemia are medical emergencies that commonly feature in negligence claims. DKA can occur due to missed insulin doses or mismanagement, leading to life-threatening conditions. Similarly, severe hypoglycemia can cause unconsciousness or death if not treated promptly. Both conditions highlight critical lapses in diabetes management within healthcare settings.

Legal Implications of Poor Diabetes Management

Poor diabetes management in healthcare settings can manifest in several ways, often leading to medico-legal claims.

  1. Monitoring Failures: Regular blood glucose monitoring is essential to prevent complications such as hypoglycemia or hyperglycemia. Hospitals must ensure that diabetic patients’ blood glucose levels are consistently within safe ranges. Failures in monitoring can lead to severe, life-threatening conditions, forming a strong basis for negligence claims.
  2. Incorrect Insulin Dosage: Administering the wrong insulin dosage can cause dangerous fluctuations in blood glucose levels. These errors often result from miscalculations, miscommunication, or inadequate supervision. Such mistakes can lead to severe outcomes, including coma or death, and are frequently cited in medico-legal cases.
  3. Neglecting Diabetic Foot Care: Diabetic patients are particularly prone to foot complications, including ulcers and infections. Proper foot care, involving regular inspections and appropriate wound management, is crucial. Failures in this area often lead to severe complications and amputations, common grounds for litigation.
  4. Inadequate Nutritional Support: Diabetic patients require specialised nutritional support to manage their condition effectively. Neglecting to provide appropriate diets and medication tailored to their needs can exacerbate their condition, delay recovery from operations, and lead to complications, often resulting in legal action.
  5. Failure to Diagnose/Manage Gestational Diabetes: Women at high risk of developing diabetes in pregnancy due to ethnicity, family history of diabetes, obesity, and maternal age need to be diagnosed and provided appropriate management. Failure can cause the foetus to gain excessive weight which will complicate delivery and, if not recognised, can result in harm or death to the baby and rarely the mother.
  6. Delayed Treatment of Diabetic Emergencies: Diabetic emergencies, such as DKA or hyperosmolar hyperglycemic state (HHS), require prompt medical intervention. Delays in recognizing and treating these conditions can result in severe complications or death, frequently leading to claims of negligence.
  7. Communication Errors: Effective communication among healthcare professionals is critical in providing coordinated care to diabetic patients. Errors in communication, such as incomplete or inaccurate handovers between shifts or between different healthcare providers, can lead to lapses in care and medical negligence claims.


In summary, the implications of diabetes in medico-legal practice are profound. Mismanagement of this complex condition can lead to severe health consequences and would constitute medical negligence if the care provided deviates from the standard of care expected from healthcare providers and as documented by NICE and other advisory bodies. Healthcare providers must always adhere to established guidelines and maintain meticulous care to prevent negligence and ensure patient safety.

About the Author

Dr. Jennings is a Consultant of Endocrinology at the York Teaching Hospital. He has held various positions including Clinical Assistant Professor at the School of Medicine in St George’s university Grenada, Chief Medical Officer at Norwich Union and Co-Leader MSc in Diabetes Care in the Department of Health Sciences at the University of York.

His research interests are Oxidative Stress, Insulin Resistance, Glucose Metabolism and Metabolic Endocrinology. To request his CV or for any medico-legal matters he can be reached at pauljennings@inneg.co.uk

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