Causes of NDM

PNDM and TNDM are inherited genetically from the mother or father of the infant. Different genetic inheritance or genetic mutations can lead to different diagnosis of NDM (Permanent or Transient Neonatal Diabetes Mellitus). The following are different types of inheritance or mutations:

- "Autosomal Dominant": Every cell has two copies of each gene-one gen coming from the mother and one coming from the father. Autosomal dominant inheritance pattern is defined as a mutation that occurs in only one copy of the gene. A parent with the mutation can pass on a copy of the gene and a parent with the mutation can pass on a copy of their working gene (or a copy of their damaged gene). In an autosomal dominant inheritance, a child who has a parent with the mutation has a 50% possibility of inheriting the mutation.

- "Autosomal Recessive" -Autosomal recessive-Generally, every cells have two copies of each gene-one gene is inherited from the mother and one gene is inherited from the father. Autosomal recessive inheritance pattern is defined as a mutation present in both copies if the gene in order for a person to be affected and each parent much pass on a mutated gene for a child to be affected. However, if an infant or child has only one copy, he or she are a carrier of the mutation. If moth parents are carriers of the recessive gene mutation, each child have a 25% chance of inheriting the gene.

- "Spontaneous": A new mutation or change occurs within the gene.

- "X-linked:" When a trait or disease happens in a person who has inherited a mutated gene on the X chromosome (one of the sex chromosome).

Prevention: There are no current prevention methods, because TNDM or PNDM are inherited genetically.

Breast feeding is good for the child even with a mother with diabetes mellitus. Some women wonder whether breast feeding is recommended after they have been diagnosed with diabetes mellitus. Breast feeding is recommended for most babies, including when mothers may be diabetic. In fact, the child’s risk for developing type 2 diabetes mellitus later in life may be lower if the baby was breast-fed. It also helps the child to maintain a healthy body weight during infancy. However, the breastmilk of mothers with diabetes has been demonstrated to have a different composition than that of non-diabetic mothers, containing elevated levels of glucose and insulin and decreased polyunsaturated fatty acids. Although benefits of breast-feeding for the children of diabetic mothers have been documented, ingestion of diabetic breast milk has also been linked to delayed language development on a dose-dependent basis.

Classical risk factors for developing gestational diabetes are:

- Polycystic Ovary Syndrome

- A previous diagnosis of gestational diabetes or prediabetes, impaired glucose tolerance, or impaired fasting glycaemia

- A family history revealing a first-degree relative with type 2 diabetes

- Maternal age – a woman's risk factor increases as she gets older (especially for women over 35 years of age).

- Ethnicity (those with higher risk factors include African-Americans, Afro-Caribbeans, Native Americans, Hispanics, Pacific Islanders, and people originating from South Asia)

- Being overweight, obese or severely obese increases the risk by a factor 2.1, 3.6 and 8.6, respectively.

- A previous pregnancy which resulted in a child with a macrosomia (high birth weight: >90th centile or >4000 g (8 lbs 12.8 oz))

- Previous poor obstetric history

- Other genetic risk factors: There are at least 10 genes where certain polymorphism are associated with an increased risk of gestational diabetes, most notably TCF7L2.

In addition to this, statistics show a double risk of GDM in smokers. Polycystic ovarian syndrome is also a risk factor, although relevant evidence remains controversial. Some studies have looked at more controversial potential risk factors, such as short stature.

About 40–60% of women with GDM have no demonstrable risk factor; for this reason many advocate to screen all women. Typically, women with GDM exhibit no symptoms (another reason for universal screening), but some women may demonstrate increased thirst, increased urination, fatigue, nausea and vomiting, bladder infection, yeast infections and blurred vision.

Sedentary lifestyle increases the likelihood of development of insulin resistance. It has been estimated that each 500 kcal/week increment in physical activity related energy expenditure, reduces the lifetime risk of type 2 diabetes by 9%. A different study found that vigorous exercise at least once a week reduced the risk of type 2 diabetes in women by 33%.

The outcome for infants or adults with NDM have different outcomes among carriers of the disease. Among affected babies, some have PNDM while others have relapse of their diabetes and other patients may experience permanent remission. Diabetes may reoccur in the patient's childhood or adulthood. It was estimated that neonatal diabetes mellitus will be TNDM in about 50% are half of the cases.

During the Neonatal stage, the prognosis is determined by the severity of the disease (dehydration and acidosis), also based on how rapidly the disase is diagnosed and treated. Associated abnormalities (e.g. irregular growth in the womb or enlarged tongue) can effect a person's prognosis. The long-term prognosis depends on the person's metabolic control, which effects the presence and complications of diabetes complications. The prognosis can be confirmed with genetic analysis to find the genetic cause of the disease. WIth proper management, the prognosis for overall health and normal brain development is normally good. It is highly advised people living with NDM seek prognosis from their health care provider.

GDM poses a risk to mother and child. This risk is largely related to uncontrolled high blood glucose levels and its consequences. The risk increases with higher blood glucose levels. Treatment resulting in better control of these levels can reduce some of the risks of GDM considerably.

The two main risks GDM imposes on the baby are growth abnormalities and chemical imbalances after birth, which may require admission to a neonatal intensive care unit. Infants born to mothers with GDM are at risk of being both large for gestational age (macrosomic) in unmanaged GDM, and small for gestational age and Intrauterine growth retardation in managed GDM. Macrosomia in turn increases the risk of instrumental deliveries (e.g. forceps, ventouse and caesarean section) or problems during vaginal delivery (such as shoulder dystocia). Macrosomia may affect 12% of normal women compared to 20% of women with GDM. However, the evidence for each of these complications is not equally strong; in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study for example, there was an increased risk for babies to be large but not small for gestational age in women with uncontrolled GDM. Research into complications for GDM is difficult because of the many confounding factors (such as obesity). Labelling a woman as having GDM may in itself increase the risk of having an unnecessary caesarean section.

Neonates born from women with consistently high blood sugar levels are also at an increased risk of low blood glucose (hypoglycemia), jaundice, high red blood cell mass (polycythemia) and low blood calcium (hypocalcemia) and magnesium (hypomagnesemia). Untreated GDM also interferes with maturation, causing dysmature babies prone to respiratory distress syndrome due to incomplete lung maturation and impaired surfactant synthesis.

Unlike pre-gestational diabetes, gestational diabetes has not been clearly shown to be an independent risk factor for birth defects. Birth defects usually originate sometime during the first trimester (before the 13th week) of pregnancy, whereas GDM gradually develops and is least pronounced during the first and early second trimester. Studies have shown that the offspring of women with GDM are at a higher risk for congenital malformations. A large case-control study found that gestational diabetes was linked with a limited group of birth defects, and that this association was generally limited to women with a higher body mass index (≥ 25 kg/m²). It is difficult to make sure that this is not partially due to the inclusion of women with pre-existent type 2 diabetes who were not diagnosed before pregnancy.

Because of conflicting studies, it is unclear at the moment whether women with GDM have a higher risk of preeclampsia. In the HAPO study, the risk of preeclampsia was between 13% and 37% higher, although not all possible confounding factors were corrected.

Several associated risk factors include the following:

- Genetic factors (inherited component):

- Family history of type 2 diabetes

- Insulin receptor mutations (Donohue syndrome)

- LMNA mutations (familial partial lipodystrophy)

- Cultural variables, such as diet varying with race and class; factors related to stress, socio-economic status and history have been shown to activate the stress response, which increases the production of glucose and insulin resistance, as well as inhibiting pancreatic function and thus might be of importance, although it is not fully corroborated by the scientific evidence.

- Particular physiological conditions and environmental factors:

- Age 40–45 years or older

- Obesity

- The tendency to store fat preferentially in the abdomen (also known as "abdominal obesity)", as opposed to storing it in hips and thighs

- Sedentary lifestyle, lack of physical exercise

- Hypertension

- High triglyceride level (hypertriglyceridemia)

- Low level of high-density lipoprotein (also known as HDL cholesterol or "good cholesterol")

- Prediabetes, blood glucose levels have been too high in the past, i.e. the patient's body has previously shown slight problems with its production and usage of insulin ("previous evidence of impaired glucose homeostasis")

- Having developed gestational diabetes during past pregnancies

- Giving birth to a baby weighing more than 9 pounds (a bit over 4 kilograms)

- Pathology:

- Obesity and overweight (BMI > 25)

- Metabolic syndrome (hyperlipidemia + HDL cholesterol level 2.82 mmol/L), hypertension (> 140/90 mmHg), or arteriosclerosis

- Liver pathologies

- Infection (Hepatitis C)

- Hemochromatosis

- Gastroparesis

- Polycystic ovary syndrome (PCOS)

- Hypercortisolism (e.g., Cushing's syndrome, glucocorticoid therapy)

- Medications (e.g., glucosamine, rifampicin, isoniazid, olanzapine, risperidone, progestogens, glucocorticoids, methadone, many antiretrovirals)

Lifestyle factors are important to the development of type 2 diabetes, including obesity and being overweight (defined by a body mass index of greater than 25), lack of physical activity, poor diet, stress, and urbanization. Excess body fat is associated with 30% of cases in those of Chinese and Japanese descent, 60–80% of cases in those of European and African descent, and 100% of cases in Pima Indians and Pacific Islanders. Among those who are not obese, a high waist–hip ratio is often present. Smoking appears to increase the risk of type 2 diabetes mellitus.

Dietary factors also influence the risk of developing type 2 diabetes. Consumption of sugar-sweetened drinks in excess is associated with an increased risk. The type of fats in the diet are important, with saturated fats and trans fatty acids increasing the risk, and polyunsaturated and monounsaturated fat decreasing the risk. Eating a lot of white rice appears to play a role in increasing risk. A lack of exercise is believed to cause 7% of cases. Persistent organic pollutants may play a role.

High blood sugar levels are harmful to the mother and her fetus. Experts advise diabetics to maintain blood sugar level close to normal range for 2 to 3 months before planning for pregnancy. Managing blood sugar close to normal before and during pregnancy helps to protect the health of mother and the baby.

Insulin may be needed for type 2 diabetics instead of oral diabetes medication. Extra insulin may be needed for type 1 diabetics during pregnancy. Doctors may advise to check blood sugar more often to maintain near-normal blood sugar levels.

In some forms of MODY, standard treatment is appropriate, though exceptions occur:

- In MODY2, oral agents are relatively ineffective and insulin is unnecessary.

- In MODY1 and MODY3, insulin may be more effective than drugs to increase insulin sensitivity.

- Sulfonylureas are effective in the K channel forms of neonatal-onset diabetes. The mouse model of MODY diabetes suggested that the reduced clearance of sulfonylureas stands behind their therapeutic success in human MODY patients, but Urbanova et al. found that human MODY patients respond differently to the mouse model and that there was no consistent decrease in the clearance of sulfonylureas in randomly selected HNF1A-MODY and HNF4A-MODY patients.

The American College of Endocrinology (ACE) and the American Association of Clinical Endocrinologists (AACE) have developed "lifestyle intervention" guidelines for preventing the onset of type 2 diabetes:

- Healthy meals (a diet with no saturated and trans fats, sugars, and refined carbohydrates, as well as limited the intake of sodium and total calories)

- Physical exercise (30–45 minutes of cardio vascular exercise per day, five days a week)

- Reducing weight by as little as 5–10 percent may have a significant impact on overall health

Since hyperinsulinemia and obesity are so closely linked it is hard to determine whether hyperinsulinemia causes obesity or obesity causes hyperinsulinemia, or both.

Obesity is characterized by an excess of adipose tissue – insulin increases the synthesis of fatty acids from glucose, facilitates the entry of glucose into adipocytes and inhibits breakdown of fat in adipocytes.

On the other hand, adipose tissue is known to secrete various metabolites, hormones and cytokines that may play a role in causing hyperinsulinemia. Specifically cytokines secreted by adipose tissue directly affect the insulin signalling cascade, and thus insulin secretion. Adiponectins are cytokines that are inversely related to percent body fat; that is people with a low body fat will have higher concentrations of adiponectins where as people with high body fat will have lower concentrations of adiponectins. Weyer "et al." (2011) reported that hyperinsulinemia is strongly associated with low adiponectin concentrations in obese people, though whether low adiponectin has a causal role in hyperinsulinemia remains to be established.

- May lead to hypoglycemia or diabetes

- Increased risk of PCOS

- Increased synthesis of VLDL (hypertriglyceridemia)

- Hypertension (insulin increases sodium retention by the renal tubules)

- Coronary Artery Disease (increased insulin damages endothelial cells)

- Increased risk of cardiovascular disease

- Weight gain and lethargy (possibly connected to an underactive thyroid)

It is estimated that between 6-50% of all persons, depending on population, diagnosed with type 2 diabetes might actually have LADA. This number accounts for an estimated 5–10% of the total diabetes population in the U.S. or, as many as 3.5 million persons with LADA. People with LADA typically have a normal BMI or may be underweight due to weight loss prior to diagnosis. Some people with LADA, however, may be overweight to mildly obese.

Contrary to popular belief, some people having LADA do carry a family history of type 2 diabetes.

At present, there is no international standard classification of diabetes in dogs. Commonly used terms are:

- Insulin deficiency diabetes or primary diabetes, which refers to the destruction of the beta cells of the pancreas and their inability to produce insulin.

- Insulin resistance diabetes or secondary diabetes, which describes the resistance to insulin caused by other medical conditions or by hormonal drugs.

While the occurrence of beta cell destruction is known, all of the processes behind it are not. Canine primary diabetes mirrors Type 1 human diabetes in the inability to produce insulin and the need for exogenous replacement of it, but the target of canine diabetes autoantibodies has yet to be identified. Breed and treatment studies have been able to provide some evidence of a genetic connection. Studies have furnished evidence that canine diabetes has a seasonal connection not unlike its human Type 1 diabetes counterpart, and a "lifestyle" factor, with pancreatitis being a clear cause. This evidence suggests that the disease in dogs has some environmental and dietary factors involved.

Secondary diabetes may be caused by use of steroid medications, the hormones of estrus, acromegaly, (spaying can resolve the diabetes), pregnancy, or other medical conditions such as Cushing's disease. In such cases, it may be possible to treat the primary medical problem and revert the animal to non-diabetic status. Returning to non-diabetic status depends on the amount of damage the pancreatic insulin-producing beta cells have sustained.

It happens rarely, but it is possible for a pancreatitis attack to activate the endocrine portion of the organ back into being capable of producing insulin once again in dogs. It is possible for acute pancreatitis to cause a temporary, or transient diabetes, most likely due to damage to the endocrine portion's beta cells. Insulin resistance that can follow a pancreatitis attack may last for some time thereafter. Pancreatitis can damage the endocrine pancreas to the point where the diabetes is permanent.

The development of type 2 diabetes is caused by a combination of lifestyle and genetic factors. While some of these factors are under personal control, such as diet and obesity, other factors are not, such as increasing age, female gender, and genetics. A lack of sleep has been linked to type 2 diabetes. This is believed to act through its effect on metabolism. The nutritional status of a mother during fetal development may also play a role, with one proposed mechanism being that of altered DNA methylation. The intestinal bacteriæ Prevotella copri and Bacteroides vulgatus have been connected with type 2 diabetes.

Some sources make a distinction between two forms of monogenetic diabetes: MODY and neonatal diabetes. However, they have much in common and are often studied together.

These are associated with insulin resistance and are risk factors for the development of type 2 diabetes mellitus. Those in this stratum (IGT or IFG) are at increased risk of cardiovascular disease. Of the two, impaired glucose tolerance better predicts cardiovascular disease and mortality.

In a way, prediabetes is a misnomer since it is an early stage of diabetes. It now is known that the health complications associated with type 2 diabetes often occur before the medical diagnosis of diabetes is made.

MODY 2 is a form of maturity onset diabetes of the young.

MODY 2 is due to any of several mutations in the "GCK" gene on chromosome 7 for glucokinase. Glucokinase serves as the glucose sensor for the pancreatic beta cell. Normal glucokinase triggers insulin secretion as the glucose exceeds about 90 mg/dl (5 mM). These loss-of-function mutations result in a glucokinase molecule that is less sensitive or less responsive to rising levels of glucose. The beta cells in MODY 2 have a normal ability to make and secrete insulin, but do so only above an abnormally high threshold (e.g., 126–144 mg/dl, or 7-8 mM). This produces a chronic, mild increase in blood sugar, which is usually asymptomatic. It is usually detected by accidental discovery of mildly elevated blood sugar (e.g., during pregnancy screening). An oral glucose tolerance test is much less abnormal than would be expected from the impaired (elevated) fasting blood sugar, since insulin secretion is usually normal once the glucose has exceeded the threshold for that specific variant of the glucokinase enzyme.

The degree of blood sugar elevation does not worsen rapidly with age, and long-term diabetic complications are rare. In healthy children and adults, a high blood sugar level can be avoided by a healthy diet and exercise, primarily avoiding large amounts of carbohydrates. However, as people who have MODY2 enter their 50's and 60's, even though they continue to eat a healthy diet and exercise, they sometimes are unable to control a high blood sugar level with these measures. In these cases, many medicines for type II diabetes mellitus are not effective, because MODY2 does not cause insulin resistance. Repaglinide (Prandin) can help the body regulate the amount of glucose in the blood by stimulating the pancreas to release insulin before meals. In some cases, the baseline glucose levels are too high as well and insulin is required.

MODY2 is an autosomal dominant condition. Autosomal dominance refers to a single, abnormal gene on one of the first 22 nonsex chromosomes from either parent which can cause an autosomal disorder. Dominant inheritance means an abnormal gene from one parent is capable of causing disease, even though the matching gene from the other parent is normal. The abnormal gene "dominates" the pair of genes. If just one parent has a dominant gene defect, each child has a 50% chance of inheriting the disorder.

This type of MODY demonstrates the common circulation but complex interplay between maternal and fetal metabolism and hormone signals in the determination of fetal size. A small number of infants will have a new mutation not present in their mothers. If the mother is affected and the fetus is not, the maternal glucose will be somewhat high and the normal pancreas of the fetus will generate more insulin to compensate, resulting in a large infant. If the fetus is affected but mother is not, glucoses will be normal and fetal insulin production will be low, resulting in intrauterine growth retardation. Finally, if both mother and fetus have the disease, the two defects will offset each other and fetal size will be unaffected.

When both "GCK" genes are affected the diabetes appears earlier and the hyperglycemia is more severe. A form of permanent neonatal diabetes has been caused by homozygous mutations in the GCK gene.

In February 2013 scientists successfully cured type 1 diabetes in dogs using a pioneering gene therapy.

Various strategies have been proposed to prevent the development of metabolic syndrome. These include increased physical activity (such as walking 30 minutes every day), and a healthy, reduced calorie diet. Many studies support the value of a healthy lifestyle as above. However, one study stated these potentially beneficial measures are effective in only a minority of people, primarily due to a lack of compliance with lifestyle and diet changes. The International Obesity Taskforce states that interventions on a sociopolitical level are required to reduce development of the metabolic syndrome in populations.

The Caerphilly Heart Disease Study followed 2,375 male subjects over 20 years and suggested the daily intake of a pint (~568 ml) of milk or equivalent dairy products more than halved the risk of metabolic syndrome. Some subsequent studies support the authors' findings, while others dispute them. A systematic review of four randomized controlled trials found that a paleolithic nutritional pattern improved three of five measurable components of the metabolic syndrome in participants with at least one of the components.

Possible causes include:

- Neoplasm

- Pancreatic cancer

- Polycystic ovary syndrome (PCOS)

- Trans fats

A 1988 study over 41 months found that improved glucose control led to initial "worsening of complications" but was not followed by the expected improvement in complications. In 1993 it was discovered that the serum of diabetics with neuropathy is toxic to nerves, even if its blood sugar content is normal.

Research from 1995 also challenged the theory of hyperglycemia as the cause of diabetic complications. The fact that 40% of diabetics who carefully controlled their blood sugar nevertheless developed neuropathy made clear other factors were involved.

In a 2013 meta-analysis of 6 randomized controlled trials involving 27,654 patients, tight blood glucose control reduced the risk for some macrovascular and microvascular events but without effect on all-cause mortality and cardiovascular mortality.

Type 1 diabetes is not currently preventable. Some researchers believe it might be prevented at the latent autoimmune stage, before it starts destroying beta cells.

The signs of diabetes mellitus are caused by a persistently high blood glucose concentration, which may be caused by either insufficient insulin, or by a lack of response to insulin. Most cats have a type of diabetes mellitus similar to human diabetes mellitus type 2, with β-cell dysfunction and insulin resistance. Factors which contribute to insulin resistance include obesity and endocrine diseases such as acromegaly. Acromegaly affects 20–30% of diabetic cats; it can be diagnosed by measuring the concentration of insulin-like growth factor-1 (IGF-1) in the blood.

People with diabetes show an increased rate of urinary tract infection. The reason is bladder dysfunction that is more common in diabetics than in non-diabetics due to diabetic nephropathy. When present, nephropathy can cause a decrease in bladder sensation, which in turn, can cause increased residual urine, a risk factor for urinary tract infections.