Study of some routine laboratory tests as markers for insulin insufficiency in type 2 diabetes

الملخص EN

BACKGROUND: Type 2 diabetes mellitus is by far the most common of all forms of diabetes mellitus which affects 3-6 % of general population.

Clearly, insulin is more effective than oral hypoglycemic drugs in type 2 diabetic patients who have ketonuria, weight loss and & or sever hyperglycemic symptoms.

However, the medical criteria for initiating insulin therapy in type 2 diabetic patients have not yet been clearly established.

Among parameters, body mass index, fasting blood glucose and plasma chloride concentration were identified as parameters for early insulin therapy in type 2 diabetic patients. AIM OF THE WORK: The aim of this study was to determine the requirements for insulin therapy in type 2 diabetic patients on the basis of statistical analysis on several clinical and routine laboratory parameters. SUBJECTS AND METHODS: This study included fifty patients with type 2 diabetes mellitus on oral antidiabetic drugs (OAD); Subjects were classified into two groups according to their requirement for insulin therapy: Group 1: Twenty five type 2 diabetic patients controlled on OAD, Group 2: Twenty five type 2 diabetic patients not controlled on OAD and requiring insulin therapy (based on repeated high HbA1c > 8; progressive weight loss; failure to control diabetes with maximum dose of more than one OAD despite diet control and proper physical activity).

None of those patients has hormonal, renal, hepatic problems or drugs (e.g.

thiazides, carbamazepine…) that affect the glycemic conditions or other.

Test parameters.

For all subjects full history taking (including duration of diabetes, history of diabetic complication…..); thorough clinical examination including anthropometric measurements {body mass index (BMI), waist ⁄ hip ratio (W/H ratio};) fasting and two hours postprandial plasma glucose (mg ⁄ dL); fasting and two hours postprandial plasma insulin (Μiu ⁄ ml); lipid profile (mg ⁄ dL); HbA1c; serum sodium (mEq ⁄ L), serum chloride (mEq ⁄ L), serum uric acid (mg ⁄ dL) and serum potassium (mEq ⁄ L).

HOMA-IR, HOMA-B % are used as parameter for insulin sensitivity and β cell function respectively according to Matthews Formula. RESULTS: the study showed that there was significant difference between group 1 and group 2 as regard serum sodium(P < 0.001),serum chloride (P < 0.001),serum uric acid (P< 0.001), plasma cholesterol (P < 0.001), plasma triglycerides (p < 0.05), fasting blood glucose(P < 0.001), two hour postprandial blood glucose (P < 0.001), HbA1c (P<0.001) fasting serum insulin (P < 0.05), two hour postprandial serum insulin (P<0.001), 0.001) HOMA-IR (P < 0.001), HOMA-β (P < duration of diabetes (P < 0.001).

There was no significant difference between two studied groups as regard age, weight, height, BMI, serum potassium (P > 0.05).

Also, it was observed that serum sodium, serum chloride, and serum uric acid respectively had a significant negative correlation with fasting blood glucose (r = - 0.89) (r = - 0.85) ( r = - 0.72), postprandial blood glucose (r = - 0.85) (r = - 0.83)( r = - 0.72) and HbA1c(r = - 0.80) ( r = -0.86)( r = - 0.73); a significant positive correlation with fasting insulin (r = 0.42)(r = 0.39)( r = 0.58), postprandial plasma insulin (r = 0.57) (r = 0.56) ( r = 0.71)and HOMA- β (r = 0.87) (r = 0.92) = (r = 0.81).

Serum potassium had no correlation with fasting blood glucose (r = 0.25), postprandial blood glucose (r = 0.27), fasting insulin (r = 0.16), postprandial insulin (r = 0.09), HbA1c (r = 0.24), HOMA –β (r= 0.14), HOMA-IR (r = 0.1), serum sodium (r = -0.17), serum chloride (-0.21) and serum uric acid (-0.11).

Also, HOMA-IR was a negatively correlated with serum sodium (r = -0.56) and serum chloride (r = -0.59) and positively correlated with serum uric acid (r = 0.29) and serum potassium (r =0.36).

Serum sodium had a positive significant correlation with serum chloride (r = 0.89) and serum uric acid (r=0.67).

In addition, serum uric acid had a positive correlation wi