According to Huether and McCance (2017), diabetes insipidus is an insufficiency of ADH activity, which leads to polyuria and polydipsia. It is also pointed out by Huether and McCance (2017) that there are two types of diabetes insipidus: neurogenic and central. According to Hui and Radbel (2019), there is a deficiency of ADH in central diabetes insipidus and in neutrogenic diabetes insipidus, ADH is available, but there is a lack of response by the kidneys. Hui and Radbel (2019) also points out that ADH regulates water balance and that ADH is produced by the posterior pituitary. According to Hui and Radbel (2019), ADH targets the kidney and binds to V-2 receptors on the renal collecting tubule which leads to signalling of G-adenyl cyclase system activation which increases cyclic 3’5′ adenosine monophosphate. This leads to phosphorylation of preformed AQP2 water channels. Huether and McCance (2017) point out that insufficient ADH activity causes excretion of large volumes of dilute urine, leading to increased plasma osmolality.
Hui and Radbel (2019), point out that the most common findings in diabetes insipidus are polydipsia, polyuria, nocturia, weakness, lethargy, fatigue, and myalgias. It is also further pointed out by Hui and Radbel (2019) that diabetes insipidus can be either congenital or acquired.
According to Huether and Mccance (2017), treatment is based on the extent of ADH deficiency, age, endocrine, and cardiovascular status. Hui and Radbel (2019) point out that treatment includes DDAVP which is an ADH analog and can be given orally, intranasally, subcutaneously, or intravenously. According to Hui and Radbel (2019), it is very essential to replete fluid losses in diabetes insipidus.
Diabetes Mellitus
Huether and McCance (2017), point out that diabetes mellitus 1 is a slowly progressive autoimmune Tcell-mediated disease that destroys beta cells of the pancreas. According to Huether and McCance (2017), the destruction of beta cells is related to genetic susceptibility and environmental factors. It is further pointed out by Huether and McCance (2017) in order for insulin synthesis to decline enough such that hyperglycemia occurs, then 80-90% of insulin secreting beta cells of the islet of Langerhans must be destroyed. According to Huether and McCance (2017), symptoms include polyuria, thirst, weight loss due to protein and fat breakdown, as well as high levels of circulating ketones leading to diabetic ketoacidosis.
According to Huether and McCance (2017), insulin resistance is defined as suboptimal response of insulin-sensitive tissues and that there are several mechanisms are involved in abnormalities in the insulin signalin pathway and contribute to insulin resistance. Huether and McCance (2017) also points out that abnormality of the insulin molecule, high amounts of insulin abnormality and alteration of glucose transporter proteins lead to insulin resistance, thereby leading to type 2 diabetes mellitus.
The treatment involves individual planning according to type of disease, age, and activity level, and all individuals require some combination of insulin therapy, meal planning, and exercise regimen for type 1 diabetes. According to Huether and McCance (2017), the treatment approach is maintaining appropriate diet and exercise program and oral hypoglycemic agents are indicated. It is further pointed out by Huether and McCance (2017), metformin is considered the primary pharmacologic choice.
Factors contributing to both diabetes insipidus and diabetes mellitus
Hammer and McPhee (2019) point out that “at least 50% of the genetic susceptibility for type 1 diabetes mellitus has been linked to the genes of major histocompatibility complex and in addition , 6% of children with high risk HLA types will develop diabetes”. According to Hammer and McPhee (2019), the genetic components underlying type 2 diabetes mellitus are much stronger than in type 1 diabetes mellitus. Huether and McCance (2017) point out that more than 60 genes have been identified that are associated with type 2 diabetes. It is further pointed out by Huether and McCance (2017) that neurogenic diabetes insipidus can be either genetic or acquired. According to Huether and McCance (2017), prevalence of type 2 diabetes is highest in American Indians and Alaska natives. Type 1 diabetes is more common in persons of Asian and African descent.
It is important for us to be able to recognize the symptoms and take a thorough history to be able to make the correct diagnosis. Patient teaching is also very important as we look at the genetic relationship .