Complications Of Diabetes: Not So Sweet

Everyone wants to have a sweet…sweet life! Okay, at least most of us do! But for people suffering from diabetes mellitus, this is unfortunately not an option.

Diabetes Mellitus is a chronic metabolic disease characterized by elevated levels of glucose in the blood. As far as the causes of this detrimental disease are concerned, diabetes can result either from auto-immune destruction of the insulin secreting cells of the pancreas, or from acquired insulin resistance. Although the pathophysiology of the disease differs according to what type of diabetes one suffers from, most of the long term complications occur in both types, regardless of the etiology of the condition in a particular patient. The complications of diabetes mellitus are multi-systemic, due to the wide involvement of glucose metabolism in all body functions.

Cardiovascular diseases

Long standing diabetes mellitus puts the subject at risk of cardiovascular diseases, and this through several mechanisms.

First of all, with the impairment of glucose metabolism in the body, fatty acids metabolism takes over with a subsequent increase in free fatty acids (triglycerides) in the blood. Similarly, there is an increased level of LDL (Low Density Lipoproteins) particles in the blood and simultaneous decreased level of HDL (High Density Liporoteins) particles. This increases the risk of cholesterol plaques formation and thus hypertension and myocardial attacks.

Insulin resistance causes an increased accumulation of lipids in the liver and the smooth muscle. It is believed that the risk of macrovascular diseases (such as hypertension, atherosclerosis and all their complications) start to develop with the onset of insulin resistance, compared to the risk of microvascular diseases which develops with the onset of persistent hyperglycemia (this is based on the “ticking clock” hypothesis formulated by Stern in 1996 and Haffner and D'Agostino in 1999)

Diabetic vasculopathy and neuropathy

Of the two phenomena, diabetic vasculopathy is the first to occur. With continuously elevated cholesterol levels (secondary to high blood sugar), there is occlusion of the peripheral vessels (in the digits and toes), which result in decreased blood provision to the peripheral tissues. As a result, the muscles and the nerves of those tissues do not get enough nutrients to survive or even perform their function, and this results in nerve damage. This is essentially how diabetic vasculopathy develops into diabetic neuropathy.

See Also: Genetics and Diabetes Mellitus

Diabetic vasculopathy and neuropathy are the most common causes of non-traumatic amputations in hospital settings. The sad thing is, generally patients only discover that they are suffering from these complications after having suffered a non-healing wound or ulcer. Unfortunately at that stage, little to no viable tissue remains in the affected toe or finger (due to vascular compromise). With ischemic tissue necrosis, the medium becomes hospitable for bacterial overgrowth and concomitant infection. Because the tissue is not viable anymore and very unlikely to respond to antibiotic treatment, the only option to save the affected limb and prevent infection spread is amputation of the affected toe/digit.

End Stage Renal disease

The mechanism of end-stage renal disease (ESRD) in diabetes mellitus is similar to that of peripheral vasculopathy and neuropathy secondary to diabetes. Here again, the microvessels are deprived from blood supply, leading to inappropriate provision of nutrients to the kidneys. As a result of that, the kidneys can suffer ischemic injury. As a result of capillary damage, the glomeruli of the kidneys thicken and start leaking albumin. Urine tests at that stage could reveal microalbuminuria. If the condition persists, then complete thickening (sclerosis) of the glomeruli occurs, a condition known as Kimmelstiel–Wilson syndrome, or nodular diabetic glomerulosclerosis; a condition that requires renal dialysis and eventually kidney transplant to ensure the patient’s survival.

Diabetic retinopathy

Diabetic retinopathy is one of the most common causes of blindness in adults aged 20-50s. Here again, microvascular injury is the cause of the incurred damage. At the beginning stages, the damage is non proliferative: micro-injury to the retinal vessels simply causes leaking of fluid in the macula, resulting in swelling. At that stage, all you might experience is blurred vision or haziness. But as the disease progresses, fibrodysplastic changes start to develop, with over stimulation of the retinal epithelium and formation of new blood vessels to sustain the retina. However, those blood vessels are not strong enough and henceforth can easily bleed and cloud the retina. In some instances, the bleeding could get worse and subsequently cause retinal detachment. On fundoscopic exam, the characteristic “cotton-wool” appearance of the retina is observed.

Laser surgery and thorough follow-up care are thought to reduce the risk of diabetes-induced blindness by 90%.

Cancer

Diabetic patients who use pioglitazone are at higher risk of some cancers, especially bladder cancer. This was demonstrated through a 2010 Consensus Report from a panel of experts selected by both the American Diabetes Association and the American Cancer Society. Similarly, patients treated with metformin were found to have a better chance of survival from cancer compared to those treated with other diabetic medications. This observation was made valid through all geographic locations, thus eliminating the “race” and “geographical location” factors. The risks were particularly reduced for the cancers of the prostate, breast and colon, but not for lung cancer. Studies have not yet demonstrated the intrinsic mechanism through which metformin provides such results.

See Also: Types of Diabetic Neuropathy

Cognitive Decline

A study performed on middle and early old age patients suffering of diabetes type 2 revealed that diabetic patients were very likely to develop brain changes similar to those observed in Alzheimer disease. Such changes included but were not limited to frontal, temporal lobes, limbic and hippocampal systems’ atrophy.

Foot Complications

High blood sugar levels, the hallmark of diabetes, can wreak havoc on the feet in various ways. The onset of neuropathy, or nerve damage, is a frequent complication. As sugar levels rise, they can impair the peripheral nerves, predominantly in the feet, leading to symptoms ranging from a slight tingling sensation to complete numbness.

The insidious nature of this complication lies in its subtlety; if the feet lose sensation, even minor injuries like cuts or blisters can go undetected, paving the way for more significant issues. Concurrently, diabetes can constrict blood circulation, which not only elongates the healing process for injuries but can also dry out the skin, making it susceptible to cracking and potential infections.

Among the more severe foot complications is the emergence of foot ulcers. These open sores, often situated on the foot's ball or the base of the big toe, can delve into deeper skin layers if neglected, leading to severe infections. Another alarming condition is Charcot's Foot, where weakened foot bones fracture effortlessly. Due to diminished sensation from neuropathy, patients may not immediately detect these fractures, leading to deformities as they continue to walk on them.

At the stage where we are with science and medicine, a cure is still to be found for diabetes. Up to now, what we do is manage the symptoms and try to live a happy life with restrictions: this is called “adapting”. Diabetes is not a fatality anymore, and medical therapy has proven to be effective in decreasing the symptoms of the disease and improving the quality of one’s life. However, failure to adhere to medical treatment will more than likely result in the development of life-threatening diabetes complications.