Is an Oral Glucose Tolerance Test Still Valid for Diagnosing Diabetes Mellitus?

BACKGROUND: We evaluated the diagnostic rate of diabetes using fasting plasma glucose (FPG), 2-hour plasma glucose (2h PG) after 75 g oral glucose tolerance test (OGTT), and glycosylated hemoglobin (HbA1c) levels, and we elucidated the pathophysiologic characteristics and risk factors that give rise to diabetes in patients with prediabetes. METHODS: The data of 236 patients who had the OGTT at Konkuk University Hospital were analyzed. Fasting, 30, and 120 minutes blood glucose levels and insulin levels were measured. The diagnostic rate of diabetes was assessed using FPG, 2h PG, and HbA1c levels. The clinical data and insulin resistance and secretion evaluations were compared using indexes according to the fasting glucose level. RESULTS: Among 236 subjects, 97 (41.1%) were diabetics and 102 (43.2%) were prediabetics. The rate of diabetes diagnosis by one of the individual criteria was 56.7%, 53.6%, and 84.5% for FPG, HbA1c, and 2h PG, respectively. When two criteria were used to diagnose diabetes, 72.2% of the diabetic patients were identified by FPG and HbA1c, while 100% were identified by FPG and 2h PG, and 91.7% were identified by 2h PG and HbA1c. The HbA1c cut-off value for 2h PG ≥200 mg/dL was 6.1%, and the FPG cut-off value was 115 mg/dL. In impaired fasting glucose subjects, the HbA1c level, Matsuda index, and insulinogenic index were associated with risk of occurrence of overt diabetes (P<0.01). CONCLUSION: This study suggests that performing additional OGTT for patients with FPG ≥110 mg/dL or HbA1c ≥6.1% is helpful to reclassify their glucose tolerance status and evaluate their potential for progressing to overt diabetes.

A Case of Emphysematous Pyelonephritis with Emphysematous Cystitis

A 68 year old male with diabetes mellitus visited our hospital due to general weakness and abdominal pain. Patient was in severe septic condition, abdominal X-ray and CT revealed gas shadow on left kidney and bladder. E-coli grew on urine culture. Thus we were able to diagnose the patient as the emphysematous pyelonephritis with emphysematous cystitis. The patient was treated with antibiotics and bilateral bladder catheter drainage. However the patient expired due to severe sepsis. Although the emphysematous pyelonephritis and emphysematous cystitis are rare disease, they result in life threatening complication in diabetic patients. Because of rarity of these diseases, the clinical and radiological classifications, the treatment and the progress are not established. These two diseases have the same causes such as diabetes mellitus or urinary tract obstruction and can be expanded due to anatomical relationships resulting in increased mortality. The authors report 68 year old male diabetic patient with emphysematous pyelonephritis with emphysematous cystitis with literature review.

Blood glucose/insulin index and carbohydrate-to-insulin ratio in Korean type 2 diabetic patients treated by continuous subcutaneous insulin infusion / 대한내과학회지

BACKGROUND: According to the results of Diabetes Control and Complication Trial, the best strategy to prevent and/or delay diabetic complications is to maintain the normal blood glucose levels. This led to emphasize the necessity of intensive management of diabetes. The purpose of the study was to determine blood glucose/insulin index and carbohydrate (CHO)-to-insulin ratios after normalization of blood glucose levels, and to select the factors to influence the blood glucose/insulin index and CHO-to-insulin ratios in Korean type 2 diabetic patients with continuous subcutaneous insulin infusion (CSII) treatment using insulin pump and CHO counting as a meal management. METHODS: Fifty-five type 2 diabetic patients who started CSII therapy checked their blood glucose levels before and after three meals, and recorded the amounts of insulin injected in fasting and each meal and the amounts of carbohydrates consumed in each meal. Actual blood glucose/insulin index and CHO-to-insulin ratio were determined using the records, and also they were calculated using Functional Insulin Treatment Training Methods (FITTM) proposed by Howorka. Calculated values were compared to actual values. The meaningful factors to influence the actual values were selected by backward stepwise regression analysis. RESULTS: The average age of the subjects was 49.9+/-12.5 years, and the duration of diabetes was 8.7+/-4.5 years. Their body mass index was 22.5+/-3.6 kg/m2. Daily insulin requirements to normalize the blood glucose levels reached to maximum levels at l0 day CSII treatment, and they were reduced and stabilized after 20 days of the treatment. The quotient K, representing insulin sensitivity, was also decreased after CSII treatment. The basal insulin index was 0.21 IU/kg at 10 days and 0.16 IU/kg at 20 days in our study, and these values were lower than the value from FITTM, 0.35 IU/kg The blood/glucose index was -2.5 mmol/L at 10 day CSII treatment, and it was decreased to -4.4 mmol/L at 20 day treatment to the stable levels. CHO-to-insulin ratio provided by FITTM was 2.59 IU/CHO exchange unit and the ratio was 3.12 IU/CHO exchange unit at 10 days, which was decreased to 1.84 IU/CHO exchange unit at 20 days in our study. CHO-to-insulin ratios at breakfast from carbohydrate counting were higher than those of lunch and dinner, and the ratios were 1.5 to 2.5 IU/CHO exchange unit. According to the stepwise regression analysis, the blood glucose/insulin index was affected by gender, age, body mass index (BMI), fasting blood glucose levels and fasting c-peptide levels, and CHO-to-insulin ratios were influenced by gender, age, BMI, post-prandial blood glucose levels and post-prandial c-peptide levels. CONCLUSIONS: CSII treatment can make blood glucose levels maintain in normal ranges in Korean type 2 diabetic patients, and can improve insulin sensitivity. Basal insulin requirements were lower and prandial insulin requirements were higher than those calculated from FITTM. This difference between Korean and the Western can be related to difference of insulin secretion from pancreas and nutrient intake.

Inappropriate Secretion of Antidiuretic Hormone in a Patient with Squamous Cell Carcinoma of the Lung mimicking Pulmonary Tuberculosis

A 71-year-old man with squamous cell carcinoma of lung mimicking pulmonary tuberculosis associated with the syndrome of inappropriate secretion of ADH(SIADH). Laboratory examination showed serum sodium concentration of 108 mEq/l. serum osmolality 247 mEg/l urine sodium concentration of 141 mEq/l urine osmolality 547 mEq/l. normal levels (<0.56 pg/ml) of serum antidiuretic hormone (ADH). ADH release was regulated normally with changes in serum osmolality. SIADH was diagnosed on the basis of hyponatremia with corresponding serum hypoosmolality and a high urine osmolality due to continuous sodium excretion. In this case, SIADH was probably induced by increased renal sensitivity to ADH and suspected high serum ANP level of unknown origin.