Signs of Diabetes in Babies

Diabetes can affect any age group. When it affects babies less than six months old it is called neonatal diabetes mellitus. This is a rare condition, affecting one in 1,00,000-3,00,000 babies.

Neonatal diabetes is a monogenetic condition;a change in one single gene leads to faulty production of insulin by the pancreas. This results in chronic high blood glucose levels.

 What are the Different Types of Neonatal Diabetes?

There are mainly two types of neonatal diabetes: transient neonatal diabetes and permanent neonatal diabetes. There is an overlap between the two. Transient neonatal diabetes presents within the first two weeks after birth. The baby needs insulin for at least two weeks and on average, it settles by around three months. It rarely persists beyond the first year. Diabetes may recur in about 50% of these babies when they are older or as adults. Glucose testing is done annually in babies and children who are in remission. During relapse, initial management is through diet or by drugs called sulphonyl ureas that can be given orally, but some children may need insulin.

In permanent neonatal diabetes, the baby is diabetic throughout its life and can either be treated with insulin or sulphonylureas.

How is Diabetes Identified in Babies?

It is difficult to diagnose diabetes in babies.

• Hyperglycaemia/high blood glucose: High blood glucose in a new-born can be due to infections or any stress the baby experienced during birth or after delivery. This transient hyperglycaemiausually settles as the underlying condition is treated. Persistence of hyperglycaemia is an important diagnostic feature that shows the baby may have neonatal diabetes. This persistence of high blood glucose is due to a shortage of insulin. Insulin is a hormone secreted from the pancreas and facilitates entry of glucose into the cells. This glucose then gets converted into energy which is required for the functioning of various organs. If insulin production is not adequate, the glucose remains in the blood, leading to hyperglycaemia.
• Intrauterine growth retardation: Insulin is needed for growth of the foetus. If there is faulty production of insulin, the foetusis likely to have severe growth retardation while still in the mother’s womb.
• Dehydration due to excessive loss of fluids through frequent urination.
• Failure to thrive: Affected babies are unable to gain weight adequately and so their growth falters.
• Breathlessness.
• Lethargy.
• Poor feeding.
• Ketoacidosis is seen in permanent neonatal diabetes. Ketosis/Ketoacidosis is usually absent in transient neonatal diabetes. Ketoacidosis is a life-threatening condition caused by abnormally high blood glucose levels. As the cells are unable to receive glucose for energy, the body starts to break down fat and muscle. This results in ketoacids entering the blood.
• Coma in severe cases.
• Macroglossia (where the tongue is unusuallylarge) insome transient neonatal diabetes babies.
• Umbilical hernia (abdominal contents, such as part of the intestine or fat tissue, project out through a weakened portion of the abdominal wall) in some transient neonatal diabetes babies.
• Some babies with transient neonatal diabetes have heart, kidney or urinary tract abnormalities, facial asymmetry, deafness, hypothyroidism etc.
• Some babies have developmental delay, epilepsy (seizures/fits) in addition to neonatal diabetes. This is called DEND syndrome. Intermediate DEND syndrome is where the baby has milder developmental delayand does not have epilepsy. Developmental delay includes muscle weakness, learning difficulties, speech and language problems etc.
• Permanent neonatal diabetes also occurs as part of syndrome disorders where other organs are also affected, e.g. IPEX syndrome, Wolcott-Rallison syndromeetc.

In older babies, a history of frequent urination, increased thirst, increased hunger, lethargy and loss of weight is usually mentioned by the parents leading to a diagnosis of diabetes.

How to Diagnose Neonatal Diabetes Mellitus:

A thorough clinical examination of the baby is mandatory. This includes taking anthropometric measurements such as head circumference, abdominal circumference, and length and weight of the baby.All babies with diabetes should be examined for any other associated syndromic features.

Laboratory Investigations:

• Persistent hyperglycaemia (>150-200 mg/dl). A blood glucose measurement should be repeatedat leasttwice.
• Glycosuria: presence of glucose in the urine.
• Ketones may be present in the urine and blood.
• Low or absent insulin levels.
• Absent or low C-peptide.
• Absent islet cell antibodies, anti-insulin antibodies and anti-glutamic acid decarboxylase antibodies.
• Low faecal elastase and increased fat content in stool of babies with underdeveloped pancreas.
• Abdominal ultrasound or MRI – to study the pancreas.
• If the baby has fits or a developmental delay, a CT scan of the brain is required.
• Molecular genetic testing of all babies with neonatal diabetes is recommended. Genetic testing will aid in management decisions. Initially, all neonatal diabetes babies are treated with insulin. After genetic testing, if the baby has been found to have Kir 6.2 or SUR 1 activating mutations, they can be transferred to sulphonyl ureas drugs (Glibenclamide) instead of continuing the insulin. Sulphonyl ureas also improves neurological development in children.
• HbA1C (a routine blood test done in diabetic patients which gives the average blood glucose over the past three months) is not advisable to be carried out on babies. Babies have high concentrations of foetal haemoglobin and this interferes with the test, giving a low HbA1C value (a false negative result).

Are Neonatal Diabetes and Type-1 Diabetes the Same?

No, they are not the same. Type-1 diabetes is usually seen in babies older than six months, children, and adolescents. It is an auto-immune condition where the body’s immune system attacks the insulin producing cells of the pancreas, leading to a total lack of insulin. To manage Type-1 diabetes, insulin injections need to be taken by the patient throughout their life.

Neonatal diabetes affects babies less than six months old. Depending on the type of mutation, the baby can either be on insulin or sulphonyl urea drugs.

References:

• Neonatal and very-early-onset diabetes mellitus. Polak M, Shield J. Seminars in Neonatology, 2004Feb; 9(1): 59-65
• Sulfonylurea Therapy Benefits Neurological and Psychomotor Functions in Patients With Neonatal Diabetes Owing to Potassium Channel Mutations. Beltrand J et al. Diabetes Care 2015 Sep; dc150837. https://doi.org/10.2337/dc15-0837
• Neonatal diabetes mellitus.Ozlu F, Tyker F, Yuksel B. Indian Pediatrics. 2006; 43:642–645