8.2 Nutrition and Chronic Endocrine Illnesses

Diabetes

The pancreas is the endocrine gland responsible for the production and secretion of insulin and glucagon. The pancreas contains islets of Langerhans, containing insulin-producing beta cells and glucagon-secreting alpha cells. These hormones fluctuate based on blood glucose levels, and an imbalance can result in negative effects. The most notable endocrine disorder is diabetes, which is one of the most common endocrine conditions in the United States (Agency for Healthcare Research and Quality, n.d.; Sapra & Bhandari, 2023). The subclassifications for diabetes clinically define each type of the disorder. The categories include type 1 diabetes (insulin-dependent diabetes), type 2 diabetes (noninsulin-dependent diabetes), and gestational diabetes (Table 8.2).

Any of the subcategories of diabetes lead to the same clinical objective finding of hyperglycemia, which is defined as a fasting serum glucose level greater than 126 mg/dL, a random glucose level greater than 200 mg/dL, or a hemoglobin A1C (HbA1c) greater than 6.5% (Agency for Healthcare Research and Quality, n.d.; Sapra & Bhandari, 2023). Many health care providers check clients’ HbA1c levels when monitoring blood glucose control and dietary modifications. Continuously elevated levels impair the beta-cell function of the pancreas, resulting in further impaired insulin secretion (Sapra & Bhandari, 2023).

Type 1 diabetes results from the destruction of beta cells in the pancreas that eliminate the production and secretion of insulin (Sapra & Bhandari, 2023). This destruction of insulin-producing cells, usually secondary to an autoimmune disease, results in a dramatic decrease of insulin and elevated glucose levels. The absence of insulin puts the client at risk for complications involving vascular and neuropathic issues and death. Type 1 diabetes requires both insulin injections and nutritional management.

Type 2 diabetes has a different etiology than type 1 diabetes and has more of an insidious onset, with layered causal effects (Sapra & Bhandari, 2023). In contrast to type 1 diabetes, type 2 diabetes results from a sensitivity or resistance to the insulin the body creates. The difference is that in type 1 diabetes, the pancreas no longer creates insulin, so insulin injections are necessary for life, whereas insulin is still produced in type 2 diabetes. However, the circulating insulin in type 2 diabetes does not respond as it should (attributed to fatty acids and proinflammatory cytokines causing glucose transportation challenges). Long-term hyperglycemia results in continued damage to the small blood vessels and the potential development of chronic complications such as kidney failure, blindness, neuropathy, and amputation. Some risk factors for the development of type 2 diabetes include obesity and the decline of organ function or receptor cells associated with aging. Other endocrinopathies, such as acromegaly and Cushing’s syndrome, are associated with diabetes and glucose intolerance, so the health care provider must assess for these in the client with diabetes.

Nutrition is the building block for disease management and care plans. Optimal diabetes management includes strict monitoring of carbohydrate intake and blood glucose levels (Sapra & Bhandari, 2023). To ensure optimal endocrine health, individuals should eat a balanced and nutrient-rich diet that includes complex carbohydrates, fiber-rich foods, lean proteins, and healthy fats (Gray & Threlkeld, 2019; Pancheva et al., 2021; Sapra & Bhandari, 2023). Portion control and mindful eating guide weight management and overall glycemic control in this client population.

Thyroid Disease

Thyroid disorders refer to abnormal function of the thyroid (Figure 8.5). The gland plays a vital role in regulating metabolic functions in the body through the production and secretion of thyroid hormones. Thyroid disorders result from insufficient or excessive production or secretion of thyroid hormones or the hormones that stimulate the thyroid to perform those functions. Treatment options for thyroid disorders depend on the specific condition and the etiology. Some medical interventions include hormone replacement therapy, antithyroid medications, radioactive iodine therapy, or surgical removal of the gland. The nurse should have a basic comprehension of thyroid function and the integral role of dietary factors.

Figure 8.5 The butterfly-shaped thyroid gland is located in the front of the neck. (credit: modification of work from Anatomy and Physiology 2e. attribution: Copyright Rice University, OpenStax, under CC BY 4.0 license)

Hyperthyroidism is defined as a low or suppressed level of TSH alongside elevated levels of T3 and T4 (Mathew et al., 2023). If the T3 level is high and the TSH level is low, but the T4 level is normal, the condition is known as T3 toxicosis. When TSH is low but the T3 and T4 levels are normal, the condition is known as subclinical hyperthyroidism. The causes of hyperthyroidism include Graves’ disease, toxic multinodular goiter, toxic adenoma, iodine-induced pituitary adenoma, and iatrogenic or drug-related causes. Graves’ disease is the most common cause and is associated with autoimmune disease. Graves’ disease triggered by autoimmune causes is mostly likely to develop in the younger population; it is more likely associated with iodine deficiency and toxic multinodular goiter when seen in older adults. The condition is more common in women and is associated with micronutrient deficiencies, including iodine and selenium. Iodine and selenium are involved in thyroid hormone development, so inadequate amounts increase an individual’s risk for thyroid complications.

Hypothyroidism is categorized as primary or secondary (Patil et al., 2023). Primary hypothyroidism results when the gland produces inadequate amounts of T4. Secondary hypothyroidism, or central hypothyroidism, results from dysfunction at the pituitary or hypothalamus level. Iodine deficiency is the most common cause of primary hypothyroidism in countries with insufficient iodine. Iodine is a vital mineral for the production of thyroid hormones. Adequate intake of iodine allows the thyroid to function effectively and prevent thyroid dysfunction such as hypothyroidism or goiter development.

In the United States, where iodine is in sufficient supply, Hashimoto’s thyroiditis, an autoimmune disease, is the leading cause (Patil et al., 2023). Other causes include medications such as lithium and amiodarone, radioactive iodine (treatment for Graves’ disease), surgical interventions, radiotherapeutics, pituitary tumors, hypothalamus-compromising tumors, TRH resistance, brain radiation therapy, and cancer drugs. Postpartum thyroiditis, a transient autoimmune condition similar to Hashimoto’s thyroiditis, affects approximately 8% of pregnant women the first year after delivery (Rad & Deluxe, 2023). Optimal well-being and thyroid function can be maintained when clients strive toward nutritional balance. A diet that includes iodine incorporates fish, dairy products, and iodized salt (Mathew et al., 2023; National Institutes of Health, 2022a).

Acromegaly

Acromegaly is a disorder caused by too much growth hormone (Adigun et al., 2023; NIDDK, 2020) and results in overgrowth of bones in the face, hands, and feet in response to excessive levels. The primary causes relate to an increase in growth hormone (GH), with the most common cause relating to a somatotroph GH-secreting adenoma of the anterior pituitary gland. Other primary causes are related to familial conditions, such as multiple endocrine neoplasia type 1, familial acromegaly, McCune-Albright syndrome, and the Carney complex (Adigun et al., 2023). Secondary causes are related to lymphoma, pancreatic-islet cell tumors, and excess growth related to specific tumors or cancers. Clients with acromegaly may have a prominent forehead (and crease), brow, prognathism (mandibular enlargement), macroglossia, thick eyelids, a large nose, a large lower lip, and voice deepening (Adigun et al., 2023).

Nutrient and dietary patterns impact the GH and IGF changes that occur with acromegaly. Caputo et al. (2021) concluded in their study that diets low in carbohydrates, such as a ketogenic diet (35 g of carbohydrates per day), were associated with a decrease in IGF while allowing levels of GH to remain stable. For appropriate management of their disease process, individuals with acromegaly should seek the advice of a registered dietitian when changing to a ketogenic diet.

Dwarfism

Dwarfism is the medical term for short stature (Jain & Saber, 2023). There are two types of dwarfism based on the client’s physical appearance: proportionate short stature and disproportionate short stature. Proportionate stature refers to the length of the client’s limbs and trunk, which are symmetrically small, whereas disproportionate stature describes a difference in length between a client’s trunk or extremities. Dwarfism has many causes, including familial inheritance, growth or puberty delay, bone disorders, systemic diseases, and idiopathic, endocrine, and genetic causes.

When dwarfism results from an endocrine disorder, the growth hormones are deficient (Jain & Saber, 2023). The hormones that promote chondrogenesis include GH, IGF, androgens, T3, and T4. Chondrogenesis impacts the growth and development of vertebrae, cartilage, hyaline, fibrous, and elastic cartilage (Jain & Saber, 2023). The GH-IGF-1 axis is the regulatory path for height. IGF is responsible for stimulation of bone elongation and soft tissue and cartilage growth; low levels of IGF correlate with short stature.

Nutritional factors support the health and well-being of individuals with dwarfism. Calcium and vitamin D maintain healthy bone growth. Because individuals with dwarfism have higher incidences of bone and joint issues, nurses should educate these clients about adequate intake of calcium and vitamin D (Caputo et al., 2021; Jain & Saber 2023). Calcium and vitamin D sources include dairy and plant-based milk products, leafy green vegetables, and fortified foods. Individuals can also obtain vitamin D through sun exposure and the intake of fatty fish.

Protein is necessary for growth and tissue repair and should make up 15% of an individual’s daily caloric intake (Caputo et al., 2021).

Addison’s Disease

The adrenal glands have two parts, the cortex and the medulla, each producing different hormones (Allen & Sharma, 2023). The adrenal cortex releases cortisol, aldosterone, and androgenic steroids, and the medulla secretes epinephrine and norepinephrine. The hypothalamus releases the corticotropin-releasing hormone, which stimulates the anterior pituitary gland to release adrenocorticotropic hormone (ACTH) from the adrenal cortex located within the adrenal glands. Aldosterone is a hormone produced by the zona glomerulosa in the adrenal cortex. It plays a role in blood pressure regulation and electrolyte maintenance through the absorption of sodium into the bloodstream and the release of potassium into the urine (Allen & Sharma, 2023). Cortisol is a glucocorticoid hormone produced in the zona fasciculata within the adrenal cortex that regulates fats, proteins, and carbohydrates used in the body while also playing a role in suppressing inflammation, blood pressure regulation, bone formation, and increasing blood glucose. Androgenic steroids are hormones produced in the zona reticularis of the adrenal cortex, and these hormones remain the precursor for estrogens in the ovaries and androgens in the testes. The adrenal medulla remains responsible for the hormone’s epinephrine and norepinephrine, which work within the body during stressful situations to stimulate the “fight-or-flight” response or the “rest-and-digest” response.

When the adrenal glands do not secrete enough (clinical definition less than 3 mcg/dL of cortisol levels with elevated ACTH) adrenal hormones, the condition is known as adrenal insufficiency (Allen & Sharma, 2023; Munir et al., 2023). Primary adrenal insufficiency is called Addison’s disease, which occurs as a result of an autoimmune response that destroys the three layers of the adrenal cortex, limiting the production and excretion of hormones. If adrenal insufficiency occurs due to too much glucocorticoid administration, the disease is secondary adrenal insufficiency.

Dietary recommendations are vital in people with primary adrenal insufficiency. The effects of Addison’s disease can lead to an imbalance of sodium, so these clients require instruction regarding salt and sodium-rich foods. If a client reaches a state of adrenal crisis, they require hydrocortisone and intravenous saline infusions.

Cushing’s Syndrome

When the adrenal cortex produces an abundance of cortisol (primary hypercortisolism), the condition is known as Cushing syndrome (Allen & Sharma, 2023; Chaudhry & Singh, 2023). Cortisol affects the transcription and translation of enzyme proteins that metabolize fats, glycogen, protein synthesis, and Krebs cycle while elevating blood glucose levels and increasing insulin resistance (Chaudhry & Singh, 2023). Clients with Cushing’s syndrome often have comorbidities such as hypertension, peptic ulcer disease, or diabetes.

Low-carbohydrate diets are recommended because they improve related conditions such as hyperglycemia, weight gain, hypertension, and insulin resistance (Dugandzic et al., 2022). Low-carbohydrate diets include 25–50 g of carbohydrates daily or around 5–10% of daily caloric intake. Clients on low-carbohydrate diets should avoid sugars, refined fats, and highly processed foods.

Diabetes

The goals of nutrition in diabetes are to manage serum glucose levels, achieve or maintain body weight goals, and delay or prevent complications (Gray & Threlkeld, 2019; Pancheva et al., 2021). Dietary adherence increases the client’s quality of life and is the best preventive against potentially developing life-threatening complications. When teaching clients with diabetes, counseling them about nutrient-rich foods is as important as teaching them which foods to avoid. Clients are often taught to adjust insulin requirements to match consumption instead of focusing on fundamental diet instruction (Gray & Threlkeld, 2019; Pancheva et al., 2021). Significant risks for complications associated with diabetes arise from poor dietary choices.

Dietary intake for people with diabetes involves consideration of both macronutrients and micronutrients (Pancheva et al., 2021). Increasing daily water intake helps regulate blood glucose levels, maintains kidney function, prevents dehydration, and helps with weight loss (Sedaghat et al., 2021). Protein recommendations are 1–1.5 g/kg body weight per day or 15–20% of total daily calories consumed (Gray & Threlkeld, 2019). The client’s kidney function or the presence of kidney disease needs assessment because most renal diets include protein restrictions.

Fat recommendations include restricting saturated fats to less than 10% of daily intake and eating good fats such as fatty fish that contain omega-3 fatty acids, avocado, nuts, and nut butters (Gray & Threlkeld, 2019; Pancheva et al., 2021). Saturated fats maintain a correlational relationship to cardiovascular disease in individuals with diabetes and are found in fast foods, red meat, and full-fat dairy foods. Saturated fat intake in the United States, including in children, is much higher than recommended (Pancheva et al., 2021). Nurses should teach clients to avoid or limit fried or fast foods, limit intake of saturated fats, use liquid vegetable oils, and consume 1 or more servings of omega-3 fats every day, such as fatty fish, walnuts, soybean oil, ground flax seeds, or flaxseed oil.

Carbohydrate intake has the most substantial influence on glucose control (Gray & Threlkeld, 2019). Recommendations for carbohydrate consumption sometimes fluctuate as differences of expert opinion do not agree on low carbohydrate versus average carbohydrate intake for diabetes maintenance and weight loss. The definition of low carbohydrate varies among experts and is not recommended for pregnant or lactating women. The current carbohydrate recommendations include 45–50% of the daily intake of carbohydrates (Gray & Threlkeld, 2019; Pancheva et al., 2021). Experts agree that people with diabetes should avoid consuming sucrose (table sugar) and sugar-sweetened beverages (particularly those that include high-fructose corn syrup) because they provide “empty” calories and can contribute to weight gain (Gray & Threlkeld, 2019). Another recommendation is to consume fructose as a monosaccharide in the form of fruits, some vegetables, and honey. The daily fiber recommendation is 20–35 g/day. Fiber can be found in raw vegetables and minimally refined grain (Gray & Threlkeld, 2019; Pancheva et al., 2021). Total fiber intake includes both dietary fiber and functional fiber. While dietary fiber is considered a carbohydrate, the lignin found in plants is not readily digested by the stomach or absorbed within the gastrointestinal tract. Functional fiber remains responsible for the physiologic benefits of fiber. Diets high in fiber are beneficial for individuals with many chronic disorders, including diabetes.

Vitamins A, E, C, and D are not associated with glycemic control or prevention of complications. However, they do limit oxidative stress and systemic inflammation in association with immune system benefits and inflammatory response. Sodium should be limited to 2300 mg/day to prevent the known correlation between the development of cardiovascular disease and hypertension associated with diabetes (Gray & Threlkeld, 2019).

Probiotics are “good” bacteria associated with fermented foods such as yogurt, kefir, and kimchi. Positive correlational studies show that with probiotic consumption, some individuals saw improvement in glycemic and serum lipid levels (Gray & Threlkeld, 2019).

Hyperthyroidism and Hypothyroidism

The National Institutes of Health [NIH] (2022a) recommends a varying dose of iodine that increases with age as well as during pregnancy. Processed canned foods may be high in sodium but do not contain iodized salt. Some multivitamins include iodine-containing kelp (seaweed). Some plant foods such as soy, cabbage, broccoli, cauliflower, and Brussels sprouts contain iodine. Too much iodine leads to thyroid gland inflammation, so nurses should monitor clients for nausea, vomiting, diarrhea, weak pulse, and coma (NIH, 2022a). Selenium deficiency or inadequate consumption can lead to thyroid dysfunction (NIH, 2022b). Selenium is added to many dietary supplements but is naturally present in Brazil nuts, seafood, organ meats, cereals, grains, and dairy products. Selenium acts as a protective mechanism against autoimmune thyroid dysfunction. Antioxidants and other micronutrients produce anti-inflammatory effects in the thyroid, and a diet high in fruits, vegetables, legumes, nuts, fish, complex carbohydrates, extra virgin olive oil, and plant-based oils is recommended for thyroid health during times of thyroid dysfunction (Bellastella et al., 2022; Osowiecka and Myskowska-Ryciak, 2023). Other micronutrient recommendations include vitamin D, vitamin B complex, vitamin A, vitamin C, magnesium, folic acid, zinc, iron, and selenium.

Nurses should also teach clients to limit saturated fatty acids, refined and processed foods, and sugar because these induce inflammation (Bellastella et al., 2022; Mathew et al., 2023; Osowiecka & Myskowska-Ryciak, 2023). Some foods cause goiter, or an enlarged thyroid gland, and thereby interfere with thyroid function (Can & Rehman, 2023). Cabbage, broccoli, and soy have been potentially linked to goiter development (Bellastella et al., 2022; Mathew et al., 2023; Osowiecka & Myskowska-Ryciak, 2023). If thyroid disease is secondary to another condition, dietary requirements should address both conditions. This emphasizes the importance of a thorough holistic assessment that includes nutrition.