Urinary iodine is associated with insulin resistance in subjects with diabetes mellitus type 2.

BACKGROUND: Diabetes Mellitus (DM) is a major health problem worldwide and its prevalence in Saudi Arabia has reached 31.6%. Patients with diabetes mellitus are at an increased risk of thyroid disease. The purpose of this study was to examine the urinary excretion of iodine in type 2 DM (T2DM) patients, and to assess the clinical implication of iodine status on T2DM. METHODS: A total of 266 adult Saudis aged 18-55 years (109 T2DM patients and 157 healthy controls) were randomly selected from the Riyadh Cohort Study. Subjects were assessed for anthropometry, morning blood chemistries including fasting glucose, and lipid profile; serum concentrations of leptin, adiponectin, resistin, insulin, aPAI, hsCRP, Ang II, TNF-α, TSH, T3, T4, urine creatinine, urine iodine were measured using specific assays. RESULTS: The concentration of urine iodine was significantly lower in T2DM than in healthy control subjects (84.6±2.3 vs. 119.4±3.4, p<0.001), which remained significant after creatinine correction and controlling for age (p=0.01). Furthermore, urinary iodine is negatively correlated with waist, hips, SAD, glucose, insulin, HOMA-IR triglyceride, resistin, angiotensin II (Ang II), and CRP, while it was positively associated with TSH. CONCLUSIONS: The decreased levels of iodine concentration in T2DM patients and its likely deleterious effects on metabolic functions calls for a systematic approach to thyroid disease screening in diabetic patients. Routine annual urinary iodine determination is recommended and should target T2DM patients at risk of thyroid dysfunction.

Blood thiamine and its phosphate esters as measured by high-performance liquid chromatography: levels and associations in diabetes mellitus patients with varying degrees of microalbuminuria.

BACKGROUND: Thiamine deficiency has been linked to microvascular complications in patients with diabetes mellitus (DM). In this study, we aim to assess blood and urine thiamine status by high performance liquid chromatography (HPLC) in patients with DM Type 1 and Type 2 (DMT1, DMT2) and to identify associations with markers of incipient nephropathy and kidney dysfunction. SUBJECTS AND METHODS: A total of 205 subjects (43 DMT1 and 162 DMT2) with and without microalbuminuria and 26 non-diabetic controls were included. Fasting blood samples were collected and anthropometric parameters were measured. Fasting blood, lipid and renal profile were determined routinely. Blood thiamine concentration, its phosphate esters and urine thiamine were quantified using HPLC. RESULTS: Blood thiamine concentrations (ng 1-1) were decreased by 75.7% and 49.6% in patients with DMT1 and DMT2, respectively [controls (54.8+/-11.4); DMT1 (41.5+/-17.9); DMT2 (27.2+/-12.7), p<0.001]. Among those with normo-albuminuria, urinary excretion of thiamine was significantly increased to 390.1 microg/ml and 1212.4 microg/ml in DMT1 and DMT2 respectively, as compared to controls (326.4 microg/ml). DMT1 and DMT2 patients with micro- albuminuria on the other hand had 2.5- and 3.4-fold increase in urinary excretion of thiamine compared to controls. CONCLUSION: Low levels of blood thiamine are present in patients with DMT1 and DMT2, and are associated with increased thiamine clearance.