Hormones And Diabetes
Hormones are vital for life but they are also the cause of many health problems, including diabetes. Their potential to cause trouble is even reflected in their name, from the Greek word horman meaning to stir up or excite.
What are hormones?
Hormones are chemical messengers that are made in one part of the body and released directly into the blood stream to act on another part of the body. While most hormones are made in endocrine glands, some are also made in organs such as the kidneys and heart, as well as in the digestive system and within our fat stores.
Over 200 different hormones or hormone-like substances have been identified in the human body which help to regulate everything from appetite, sleep-wake cycles and fluid balance to growth, reproduction and even our moods.
Some hormones work within seconds by speeding up metabolic reactions (eg epinephrine, formally known as adrenaline), regulate blood sugar levels (eg insulin, glucagon) while others work more slowly by switching on genes to produce certain proteins (eg oestrogen, testosterone).
You need to produce just the right amount of hormones to meet conditions within your body from minute to minute. This is partly regulated by the pituitary gland which produces at least ten hormones that help to control hormone production in other glands. The function of some pituitary hormones is still not fully understood however, such as beta-endorphin which is believed to suppress pain
Researchers are actively seeking new hormones which may hold the key to preventing or curing common illnesses such as high blood pressure, diabetes, obesity and cancer. Interestingly, some hormones have different receptors in different parts of the body, which has led scientists to look for new, hormone-like drugs that can selectively switch on a receptor in one tissue (eg oestrogen receptors bones) while ignoring those in another (eg the breast).
Your metabolic hormones control normal processes of metabolism and regulate blood levels of substances such as glucose and sodium. The hormone glucagon raises your blood glucose level while insulin hormone lowers it, for example.
An inability to produce insulin hormone leads to diabetes type 1, while insulin resistance (where the pancreas still produces insulin but body cells do not respond to it) is linked with diabetes type 2.
Apart from insulin, the best known metabolic hormones are those from the thyroid gland: thyroxine and tri-iodothyronine which control your metabolic rate. An underactive thyroid gland leads to slowing up, weight gain and sensitivity to the cold, while an overactive gland (thyrotoxicosis) leads to weight loss, restlessness, sensitivity to heat and irritability.
The thyroid also produces another hormone, calcitonin, which helps to lower blood calcium levels, in contrast to parathormone (from the parathyroid glands) which raises blood calcium levels. Abnormalities in calcium regulation can lead to muscle spasms and tetany (if too low) or osteoporosis and kidney stones if too much calcium is mobilised into the blood stream.
Diabetes and thyroid problems often go hand-in-hand. This is partly because thyroid hormones are thought to play a role in insulin secretion and partly because both conditions can be associated with the production of auto-antibodies aimed against body tissues. In the general population, around 10% of people test positive for thyroid autoantibodies. Among people with either type 1 or type 2 diabetes, however, as many as 40% to 50% have thyroid antibodies. Many people with thyroid antibodies will not develop obvious symptoms but they may find it more difficult to maintain good diabetes control as a result. Your doctor may therefore check your thyroid function from time to time, especially if you find it difficult to achieve good glucose control.
Vitamin D can also be classed as a metabolic hormone as it is made in your skin, modified in the liver and kidneys and then passes into the blood stream to have an effect elsewhere – helping to control calcium absorption in the gut.
Your pineal gland makes melatonin, which helps to regulate the body’s sleep-wake cycle and therefore plays an indirect role in secretion of growth hormone which is mainly secreted during sleep – one reason why teenagers spend so much time lying in bed.
In addition, your stomach and intestines secrete a variety of hormones involved in enzyme production during digestion (eg gastrin, secretin, motilin) and are needed for healthy digestion. More recently discovered metabolic hormones include leptin, produced in body fat cells, which help to control food intake and metabolic rate. It is possible that abnormalities related to these intestinal hormones may be involved in obesity and type 2 diabetes.
Fluid and salt regulating hormones
A number of hormones are involved in water and salt balance in the body, which in turn is linked with maintaining blood pressure which is often raised in people with diabetes.
The pituitary glands produce vasopressin (antidiuretic hormone) which tells the kidneys to conserve fluid by reducing urine production. The kidneys, in turn, produce renin, a hormone that, when converted into a protein, angiotensin, constricts arteries to raise blood pressure. The adrenal glands also produce aldosterone, a hormone that regulates salt balance when stimulated by angiotensin – all these hormones form a complex interaction whose effects can last for days. More recently, scientists have discovered that the heart produces hormones such as atriopeptin that also help to regulate blood pressure and fluid balance.
Poor control of salt and fluid balance can lead to fluid retention with puffiness or extreme swelling of the body, or it can contribute to dehydration. Excess production of aldosterone can lead to low levels of potassium which can cause heart rhythm abnormalities and muscle weakness, while lack of aldosterone can lead to dangerously high levels of potassium and excessive loss of sodium and water.
Poor regulation of fluid and sodium can also lead to hypertension – especially if you follow a high salt diet and you are among the estimated one in two people whose kidneys cannot flush away excess sodium efficiently.
Your adrenal glands produce several hormones involved in controlling responses to physical and emotional stress – cortisol, epinephrine (formerly known as adrenaline) and norepinephrine (noradrenaline). When confronted with a stressful situation, blood levels of epinephrine increase by as much as 1000 fold within one minute to prepare you for physical activity as part of the so-called fight or flight reaction. As part of this response, your blood pressure and glucose levels will rise. When you have diabetes, prolonged stress can worsen your glucose control.
If stress continues for any length of time, the adrenal glands increase their output of the steroid hormone, cortisol – a rise that seems to be essential for survival. These stress hormones prime you for vigorous activity and can be reset back to ‘rest and digest’ mode by exercise.
A number of hormones are involved in sexual maturity and reproduction, including dehydroepiandrosterone (DHEA), oestrogens (oestradiol, oestrone, oestriol), progesterone and androgens such as testosterone, androstenedione and dihydrotestosterone.
While testosterone is known as the male hormone it is also present in women in significant amounts. Testosterone appears to play a role in insulin sensitivity. Men with low levels of testosterone are prone to abdominal obesity with insulin resistance, glucose intolerance, high blood pressure, abnormal blood fat levels (raised triglycerides and LDL-cholesterol) and increased blood stickiness. Put these metabolic risk factors together, and men with low testosterone levels have a significantly increased risk of developing both coronary heart disease and type 2 diabetes.
Where possible, hormone imbalances are treated with hormone replacement therapy such as in the case of insulin, thyroxine, calcitonin, oestrogen, testosterone and growth hormone deficiencies. Where hormone replacement is not possible, drugs may be given to help offset the side effects of abnormal hormone levels.
Diet can have a profound effect on hormone balance, and is linked with the development of some hormone problems such as insulin resistance in type 2 diabetes. Sex hormone balance can be influenced by the:
- types of fat and fibre you eat
- natural plant hormones present in your food
- amount of essential fatty acids you obtain
- amount of vitamins, minerals and trace elements you obtain
For a healthy hormone balance, aim to:
- Eat a healthy, low-fat diet (preferably organic) providing at least 5 portions of fruit and vegetables per day
- Obtain essential fatty acids and other building blocks for making hormones from nuts, seeds, pulses and fish
- Increase your intake of soy and other foods containing plant hormones – especially other types of beans, chickpeas, sweet potatoes and flax seeds.
- Obtain probiotic bacteria which have a modulating effect on hormone balance.
- Avoid or limit your intake of sugar and salt
- Avoid convenience, pre-processed foods and additives – eat home-made meals as much as possible
- Reduce your intake of alcohol
- Reduce your intake of caffeine to no more than 2 or 3 caffeinated drinks per day.
- Take a multivitamin and mineral supplement designed for your time of life
- Never skip a meal, especially breakfast
- Drink plenty of fluids, especially water