Some Important Case Studies
39
39.1 Case Studies of Sugar Impairment.....................
Q.1. A diabetic patient on insulin therapy was brought to the hospital in a
semiconscious state. He was sweating profusely and had tremors of hands.
What is the possible diagnosis?
Ans: The possibility is hypoglycemia due to excessive dose of insulin.
Q.2. An apparently healthy man underwent for routine laboratory investigations.
The results showed that his fasting blood sugar level was 85 mg/dl while
urine constituents were normal. However, his postprandial blood sugar after
one-and-half hours of food intake was observed to be 155 mg/dl, and urine
sample at that time was also positive for Benedict’s test. What is the
diagnosis?
Ans: The case symptoms indicate toward renal glycosuria. In renal glycosuria,
glucose is excreted in the urine despite the fact that blood glucose levels are
normal or even low. With normal kidney functions, only very high blood
glucose levels can cause its excretion in urine. So, renal glycosuria suggests
abnormal functioning of the renal tubules. Normal renal threshold for
glucose is 180 mg/dl, but in this case renal threshold is lowered.
Q.3. A 35-year-old female was examined for the laboratory tests. The report
showed that her blood sugar (fasting) was 90 mg/dl and blood sugar (P.P.)
was 168 mg/dl. The urinary analysis showed absence of urine sugar
(fasting), but in postprandial state urine was significantly positive for
sugar. Comment on report.
Ans: In this case, the fasting blood sugar is within normal limits, and urine is
negative for reducing sugars. However, under postprandial condition, the
urine tests positive for sugar although blood sugar is less than the normal
renal threshold for glucose (180 mg/dl). This indicates that renal threshold
for glucose in this patient has been lowered and it is a case of renal
glycosuria.
#Springer Nature Singapore Pte Ltd. 2018
V. Kumar, K. D. Gill,Basic Concepts in Clinical Biochemistry: A Practical Guide,
https://doi.org/10.1007/978-981-10-8186-6_39
157