WHAT IS DIABETES MELLITUS?
Diabetes mellitus is a disease of antiquity. It is a metabolic disorder of multiple etiologies. It is characterized by hyperglycemia with disturbances in the carbohydrate, fat, and protein metabolism, resulting from defects of insulin secretion, insulin action or both. The relative contribution of these defects varies between different types of diabetes. The characteristic clinical presentation is with polyuria, polydipsia, polyphagia, blurred vision, and unexplained weight loss.
WHAT CAUSES DIABETES?
Modifiable risk factors such as obesity, unhealthy diet and physical inactivity are the main non-genetic determinants of Type 2 Diabetes. Genetic predisposition plays an important part in the risk of developing Type 2 Diabetes.
Obesity (body-mass index [BMI] ≥30 kg/m2) is the strongest risk factor for Type 2 Diabetes and is associated with metabolic abnormalities resulting in insulin resistance.
A sedentary lifestyle is another risk factor for the development of Type 2 Diabetes. The primary benefits of physical activity in delaying the onset of Type 2 Diabetes include increased glucose uptake in muscles and reducing notorious intra-abdominal fat. Moderate-intensity exercise improves glucose uptake by 40%.
On the other hand, Type 1 Diabetes Mellitus is a T-cell mediated autoimmune disease in which destruction of pancreatic beta-cells causes absolute insulin deficiency which leads to hyperglycemia and a tendency to ketoacidosis. Type 1 Diabetes commonly presents in childhood or adolescence; however, the disease can appear at any age. Individuals at increased risk of developing Type 1 Diabetes can be identified by genetic markers and by the presence of characteristic autoantibodies.
HOW IS DIABETES DIAGNOSED?
The diagnosis of diabetes in an asymptomatic individual should never be made based on a single abnormal blood glucose value. Diabetes may be diagnosed based on fasting plasma glucose ≥ 7.0 mmol/L (126 mg/dL) or 2-h plasma glucose ≥ 11.1 mmol/L (200 mg/dL) during an OGTT or A1c ≥ 6.5% or in a patient with classic symptoms of hyperglycemia, a random plasma glucose ≥11.1 mmol/L (200 mg/dL).
IS SCREENING FOR DIABETES RECOMMENDED?
Measuring islet autoantibodies in individuals genetically at risk for Type 1 diabetes identifies individuals who may develop Type 1 diabetes. Such testing, coupled with education about diabetes symptoms and close follow-up, may enable earlier identification of Type 1 diabetes onset. However, there is currently a lack of accepted and clinically validated screening programs outside of the research setting; thus, widespread clinical testing of asymptomatic low-risk individuals for Type 1 diabetes is not currently recommended due to lack of approved therapeutic interventions.
Testing for prediabetes and/or Type 2 diabetes in asymptomatic people should be considered in adults of any age with overweight or obesity (BMI ≥25 kg/m2) and who have one or more additional risk factors for diabetes.
Patients with prediabetes (A1C ≥5.7%, IGT, or IFG) should be tested yearly.
Women who were diagnosed with Gestational Diabetes Mellitus should have lifelong testing at least every 3 years.
For all other people, testing should begin at age 35 years. If results are normal, testing should be repeated at a minimum of 3-year intervals, with consideration of more frequent testing depending on initial results and risk status.
WHAT ARE THE TYPES OF DIABETES?
Type 1 Diabetes Mellitus: Due to autoimmune beta-cell destruction, usually leading to absolute insulin deficiency.
Type 2 Diabetes Mellitus: Due to a progressive loss of adequate beta-cell insulin secretion frequently on the background of insulin resistance.
Gestational Diabetes Mellitus: Diabetes diagnosed in the second or third trimester of pregnancy that was not clearly overt diabetes prior to gestation.
Specific Types of Diabetes: Monogenic diabetes syndromes, diseases of the exocrine pancreas and drug- or chemical-induced diabetes.
WHAT IS INSULIN RESISTANCE AND HOW CAN WE MEASURE IT?
Insulin resistance is central to pathogenesis of cardiometabolic disease and confers increased risk of type 2 diabetes and cardiovascular disease.
Insulin resistance is defined as “a state in which a greater than normal amount of insulin is required to elicit a quantitatively normal response. Insulin resistance is a hallmark of Type 2 diabetes. Obesity escalates the pathogenesis of Type 2 diabetes through stimulation of insulin resistance.
The Euglycemic Hyperinsulinemic Clamp is considered the gold standard for measuring insulin resistance. However, it is a nonphysiologic test that is operator-dependent, time-consuming, expensive, requires intravenous infusions and limited to populations that can tolerate the procedure safely even with appropriate assent or consent.
Homeostasis Model of Insulin Resistance (HOMA-IR) test is clinically attractive because it is very easy to perform. HOMA-IR is computed with the formula using fasting plasma glucose and fasting serum insulin levels. Low HOMA-IR values indicate high insulin sensitivity, whereas high HOMA-IR values indicate low insulin sensitivity (insulin resistance).
HOW IS DIABETES TREATED?
For Type 1 Diabetes Mellitus, a multidisciplinary team trained in pediatric diabetes management and sensitive to the challenges of children and adolescents with Type 1 Diabetes and their families should provide diabetes specific care for this population. Individualized medical nutrition therapy is recommended for children and adolescents with Type 1 Diabetes as an essential component of the overall treatment plan. The only treatment option available for people with Type 1 Diabetes Mellitus is with multiple daily injections of prandial and basal insulin, or continuous subcutaneous insulin infusion throughout their life.
Diet, physical activity, and behavioral therapy to achieve and maintain ≥5% weight loss is recommended for most people with Type 2 diabetes and overweight or obese.
For Type 2 Diabetes Mellitus, first-line therapy depends on comorbidities, patient-centered treatment factors, and management needs and generally includes metformin and comprehensive lifestyle modification. Early combination therapy can be considered in some patients at treatment initiation to extend the time to treatment failure. Consider the effects on cardiovascular and renal comorbidities, efficacy, hypoglycemia risk, impact on weight, cost and access, risk for side effects, and patient preferences.
The early introduction of insulin should be considered if there is evidence of ongoing catabolism (weight loss), if symptoms of hyperglycemia are present, or when A1C levels (>10%) or blood glucose levels ≥16.6 mmol/L (≥300 mg/dL) are very high.
CAN DIABETES MEDICATIONS CAUSE ANY SIDE EFFECTS?
There are some mild side effects associated with antidiabetic medicines like gastrointestinal intolerance due to bloating, abdominal discomfort, and diarrhea; these can be mitigated by gradual dose titration. Some old generation antidiabetic medicines can cause weight gain and hypoglycemia. One of the common side effects mostly with old generation insulins is hypoglycemia. All patients are different, so, the treatment must be individualized, not generalized.
CAN DIABETES BE REVERSED?
Type 1 Diabetes Mellitus cannot be reversed.
Type 2 Diabetes Mellitus has long been regarded as a chronic, irreversible illness, requiring a continuous titration of add-on pharmacotherapy, and which inexorably progresses in over 50% of patients to insulin dependence within 9–10 years. Respected organizations like the World Health Organization and Diabetes UK now openly acknowledge that diabetes is metabolically reversible – at least for a period.
The consensus position now defines remission as being a return to below the World Health Organization/American Diabetes Association original diagnostic thresholds for diabetes and this return should be maintained for three months without any glucose-lowering pharmacotherapy. Measurement of either HbA1c or blood glucose can be used to confirm remission. It is important to note that the term “cure” has not been applied to Type 2 Diabetes, as weight regain is always a risk factor for its recurrence. Although the terms “reversal” and “remission” are used interchangeably, recent consensus supports the use of “remission” in the context of Type 2 Diabetes.
IS DIABETES THE SILENT PANDEMIC IN OMAN?
Yes, diabetes is a silent pandemic in Oman as numbers are growing very fast due to unhealthy dietary habits, sedentary lifestyle, overweight and obesity.
I personally believe that regular physical exercise and a healthy lifestyle is key to prevent Type 2 Diabetes Mellitus.