Diabetes Mellitus means your blood glucose, also called blood sugar, is too high. Your body uses glucose for energy. This is an important cause of disability and increases the risk of heart and kidney diseases and other health problems. There are three main types;
- Type 1 diabetes often starts at a young age and is due to a lack of insulin. It accounts for 10-15% of all cases of diabetes.
- Type 2 diabetes starts with resistance to the action of insulin and is associated with older age, overweight, and obesity. The case of type 2 diabetes is increasing rapidly in Nigeria. The largest part of the increase is due to poor diet (specifically excess energy intake), low levels of physical activity and the resulting increase in levels of obesity. Type 2 diabetes is much more common at older ages.
- Gestational diabetes is a type of diabetes that develops only during pregnancy, is usually diagnosed during late pregnancy. If you are diagnosed with diabetes earlier in your pregnancy, you may have had diabetes before you became pregnant
Typical complaints experienced
- Polyuria which is excessive urination, especially at night-time (more than 3 times)
- Polydipsia which is drinking water more than usual due to feeling thirsty more than usual
- Blurry vision
- Dysuria which is discomfort while urinating
- Weight loss or weight gain
Physical examination can reveal one or more of the following;
- Obesity (BMI greater than 29)
- increased blood pressure above 140/90
- Loss of sensation especially to vibration and light touch
- Signs of dehydration (loss of skin elasticity, dry mouth, muscle aches, concentrated urine)
- Lower extremity edema (swelling)
- Rash especially acanthosis nigricans which occur on her neck or around the armpit thickened, velvety, relatively darker areas of skin on the neck, armpit and in skin folds
A urine dipstick shows 0+ protein, 0+ ketones, and 3+ glucose; her non-fasting blood glucose is 180 mg/dL. A basic metabolic panel does not demonstrate renal failure (her creatinine is 0.9 and her BUN is 9) or acidosis.
You make a tentative diagnosis of chronic hyperglycemia due to type 2 diabetes. A fasting glucose test done the next day confirms the diagnosis (140 mg/dL, higher than the WHO criteria for diagnosis of equal to or great than 126 mg/dL; with her symptoms, a random blood glucose of equal to or greater than 200 mg/dL would also have been diagnostic) (1,2).
What is the most reasonable initial management of your patient’s diabetes
Mrs. S. will need a thorough discussion about diabetes, how it is treated, and why it is important to continue with these therapies even once she feels better. If her glucose was very elevated (to the >300 range) and she had signs of hypovolemia, or if she had acidosis with or without renal impairments on her labs, treatment with insulin and intravenous fluids to rapidly correct her blood glucose and prevent complications would be indicated. Mrs. S. does not appear to be dehydrated on exam, so she may be told to increase her intake of non-sugary fluids for a few days, and started on metformin. She should also be advised on increasing her exercise (for example, walking for an hour every evening), and on specifics of an appropriate diet (see answer C for more information on diet).
The use of oral medications to lower blood glucose has been shown in a number of trials to reduce the risk of diabetic complications; it may also reduce the risk of death in some populations, though this effect has not been demonstrated as thoroughly (1).
In general, metformin is presently the preferred starting medication for most (BMI of 25 or greater) patients with type 2 diabetes (1,2) who do not require insulin. When compared to other medications in trials, metformin is associated with essentially no hypoglycemia, less weight gain (often weight loss, in fact), and potentially a greater reduction in the risk for complications of diabetes. Due to a rare risk of lactic acidosis, it should be used cautiously in patients with impaired kidney function (estimate glomerular filtration rate of equal to or less than 45 ml/min/1.73 m2) (1).
It often causes diarrhea, abdominal cramping, and nausea/vomiting. These symptoms usually wane with time, and can be reduced by starting with a low dose (500mg once or twice a day, taken with food) and increasing the dose over several weeks (maximum of 2500 mg/day, split into two to three doses). Mrs. S. should be warned about these adverse effects and the importance of taking the medicines should be emphasized.
The glycemic control goal, depending on the guidelines used, is to aim for a HbA1c of 7% or less (1, 2), or a fasting plasma glucose of <115 mg/dL (1) or 70-130 mg/dL (2), or a plasma glucose two hours after a meal of <160 mg/dL (1) or <180 mg/dL (2).
In a low-resource setting such as Haiti, where more intensive monitoring is not possible, where the dangers of hypoglycemia are higher, and where the long-term benefits of ultra-aggressive glycemic control are unclear, a HbA1c goal of 7% is a reasonable target; Table 1 shows the correlation between HbA1c and the average sugar through the day. If HbA1c cannot be measured, a fasting plasma glucose can be substituted as a crude alternative (in which case the goal of a fasting plasma glucose <130 (mg/dL) would be the target); note that HbA1c is the preferred lab test to monitor long-term glycemic control whenever possible, and that fasting plasma glucose values can be skewed by prior meals, exercise, and infection. Because it is a long-term measure, HbA1c when avaiable should only be checked every three months (2).
Should Mrs. S. ever have low sugars or if there are difficulties in monitoring her sugars, more relaxed goals are reasonable to set, particularly when using agents that can cause hypoglycemia. If she cannot reach her glycemic target after a maximal dose of metformin for several months, a sulfonylurea can be added to her regimen.
Table 1. Estimated average blood glucose based on hemoglobin A1c percent