Neoplasia is a disorder that:

Choice A reason: While protein metabolism can be affected in diabetes, excess protein in the blood is not the primary mechanism increasing infection risk. Pathogens generally thrive more in high-glucose environments rather than high-protein conditions.

Choice B reason: Excess glucose in the blood creates an optimal environment for many pathogens to proliferate rapidly. High blood sugar levels weaken the immune system by impairing the function of white blood cells, making it harder for the body to fight off infections. This is particularly significant in the microvascular and macrovascular systems where the blood vessels can become damaged, further compromising immune response.

Choice C reason: Diabetic individuals do not necessarily produce fewer white blood cells. However, the functionality of these cells can be impaired by hyperglycemia, reducing their ability to fight off infections effectively.

Choice D reason: While high levels of glycosylated hemoglobin (HbA1c) indicate poor blood sugar control over a long period, the destruction of white blood cells is not the primary reason for increased infection risk. The issue lies more with the impaired function of white blood cells and the conducive environment that excess glucose provides for pathogens.

Choice A reason: Cataract development is a common issue in people with diabetes due to the high blood sugar levels that affect the lens of the eye. However, it is not the primary cause of visual impairment. Cataracts cause the lens to become cloudy, leading to blurred vision, but the impact is generally less severe compared to the microvascular complications of diabetes.

Choice B reason: Exophthalmos, or bulging of the eye, is not typically associated with diabetes. It is more commonly seen in conditions like Graves' disease, an autoimmune disorder affecting the thyroid. Therefore, while it is important to be aware of various conditions that can impact eye health, exophthalmos is not a primary complication of diabetes.

Choice C reason: Abnormal metabolism in the lens can contribute to the formation of cataracts, but it is not the main reason for diabetic visual impairment. The primary issue in diabetes-related visual impairment is damage to the small blood vessels in the retina, not just changes in the lens metabolism.

Choice D reason: Microvascular changes in the eye, particularly diabetic retinopathy, are the primary cause of visual impairment in people with diabetes. High blood sugar levels can damage the blood vessels in the retina, leading to leakage, swelling, and the formation of new, abnormal blood vessels. This can result in significant vision loss and even blindness if not properly managed. Regular eye examinations and control of blood glucose levels are crucial in preventing and managing diabetic retinopathy.