Determination of amphetamines, opioids, cocaine metabolites and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol in urine using biocompatible solid-phase microextraction and ultra-performance LC-MS/MS.

Background: Workplace drug testing primarily relies on urine analysis, targeting multiple compounds with varying physicochemical characteristics. Biocompatible solid-phase microextraction (BioSPME) is a miniaturized solid-phase extraction technique that enables the simultaneous extraction and preconcentration of analytes directly from the biological matrix. Methods: The BioSPME procedure consisted of the sequential extraction of 50-µl urine samples using LC Tips C18 in basic and acidic pH, followed by desorption with methanol and n-hexane, respectively. The extracts were analyzed by ultra-performance LC-MS/MS. Results: Intra-day precision was 1.2-8.6% and inter-day precision was 1.8-14.2%. Accuracy was 96.8-107.4%. The extraction yields were 62.8-109.4%. The matrix effects were -3.98% to 1%. Conclusion: BioSPME shows promise as an alternative method for preparing urine samples prior to drug measurement by ultra-performance LC-MS/MS.

The Ala54Thr polymorphism of the FABP2 gene influences the postprandial fatty acids in patients with type 2 diabetes.

CONTEXT: The Ala54Thr polymorphism of FABP2 gene increases affinity of intestinal fatty acid-binding protein 2 for long-chain dietary fatty acids (FA) in subjects without diabetes. OBJECTIVE: Our objective was to evaluate whether the Ala54Thr polymorphism of the FABP2 gene influences the FA composition in chylomicrons after a standard meal in patients with type 2 diabetes. METHODS: This clinical trial studied 11 patients with TT and 15 patients with AA genotypes for Ala54Thr polymorphism of FABP2 gene selected from a Brazilian type 2 diabetic cohort. FA in chylomicrons (gas chromatography), plasma glucose, and serum triglycerides were measured after an overnight fast at baseline and, after a standard test meal, at 2-h intervals during 8 h. RESULTS: During the test meal, the curves response of unsaturated FA of patients with TT genotype were different from patients with AA genotype: only patients with TT genotype exhibited an increase, with a postprandial peak at 6 h in monounsaturated FA [0.479 (0.248-0.709) to 1.674 (0.698-2.650) g/liter], polyunsaturated FA [0.338 (0.154-0.522) to 1.827 (0.389-3.265) g/liter], and trans-unsaturated FA [0.025 (0.013-0.037) to 0.122 (0.040-0.205) g/liter] (generalized estimating equations for repeated measurements: P<0.05 for all). The increase of saturated FA did not reach statistical significance. Diabetes treatment, previous diet, FA at baseline, and the increase of plasma glucose and triglycerides during the test meal were not different between TT and AA genotypes. CONCLUSIONS: The TT genotype in Ala54Thr polymorphism of FABP2 gene in patients with type 2 diabetes increased dietary FA absorption, and this might increase the susceptibility to the effects of dietary lipids.

Sources of protein and polyunsaturated fatty acids of the diet and microalbuminuria in type 2 diabetes mellitus.

BACKGROUND: Albuminuria excretion rate above the reference range and below albustix positive proteinuria (20-199 microg/min) is known as microalbuminuria and has been associated with an increased risk of death and progression to renal failure. Besides hyperglicemia and high blood pressure levels, dietary factors can also influence albuminuria. OBJECTIVE: To evaluate possible associations of dietary components (macronutrients and selected foods) with microalbuminuria in type 2 diabetic patients. METHODS: In this cross-sectional study, 119 normoalbuminuric [NORMO; 24-h urinary albumin excretion (UAE) < 20 microg/min; immunoturbidimetry] and 62 microalbuminuric (MICRO; UAE 20-199 microg/min) type 2 diabetic patients, attending the Endocrine Division, Hospital de Clínicas de Porto Alegre (Brazil), without previous dietary counseling, underwent 3-day weighed-diet records, and clinical and laboratory evaluation. RESULTS: MICRO patients consumed more protein (20.5 +/- 4.4 vs. 19.0 +/- 3.5% of total energy; p = 0.01) with a higher intake from animal sources (14.5 +/- 4.7 vs. 12.9 +/- 3.8% of total energy; p = 0.015) than NORMO patients. The intakes of PUFAs (8.6 +/- 2.9 vs. 9.7 +/- 3.3% of total energy; p < 0.03), PUFAs from vegetable sources (7.3 +/- 3.4 vs. 8.6 +/- 3.7% of total energy; p = 0.029), plant oils [0.2 (0.1-0.6) vs. 0.3 (0.1-0.9) mg/kg weight; p = 0.02] and margarines [3.3 (0-75.7) vs. 7.0 (0-51.7) g/day; p = 0.01] were lower in MICRO than in NORMO. In multivariate logistic regression models, adjusted for age, gender, presence of hypertension and fasting plasma glucose, intake of total protein (% of total energy; OR 1.104; 95% CI 1.008-1.208; p = 0.032) was positively associated with microalbuminuria. The intakes of total PUFAs (% of total energy; OR 0.855; 95%CI 0.762-0.961; p = 0.008), PUFAs from vegetable sources (% of total energy; OR 0.874; 95%CI 0.787-0.971; p = 0.012) and plant oils (mg/kg weight; OR 0.036; 95% CI 0.003-0.522; p = 0.015) were negatively associated with microalbuminuria. CONCLUSIONS: In type 2 diabetic patients, the high intake of protein and the low intake of PUFAs, particularly from plant oils, were associated with the presence of microalbuminuria. Reducing protein intake from animal sources and increasing the intake of lipids from vegetable origin might-reduce the risk of microalbuminuria.

Endothelial dysfunction and serum fatty acid composition in patients with type 2 diabetes mellitus.

The aim of this study was to evaluate the possible association between serum fatty acids composition and endothelial dysfunction in patients with type 2 diabetes mellitus. A cross-sectional study was conducted with 125 normo- or microalbuminuric type 2 diabetes mellitus patients with serum creatinine <1.5 mg/dL. Serum fatty acids composition (gas chromatography), serum levels of endothelin-1 (ET-1) (enzyme-linked immunosorbent assay), fibrinogen, serum C-reactive protein, lipids, homeostasis model assessment resistance index (HOMA-R), and 24-hour urinary albumin excretion rate were measured. Serum levels of ET-1 were positively correlated with saturated fatty acids (r = 0.257, P = .025) and negatively correlated with polyunsaturated fatty acids (PUFAs) (r = -0.319, P = .005). Serum ET-1 levels were also positively correlated with systolic blood pressure, waist circumference, total cholesterol levels, triglycerides, and HOMA-R. In multiple linear regression models, only saturated fatty acids (R(2) = 0.317, P = .002) or PUFAs (R(2) = 0.314, P = .001) remained associated with ET-1 levels. Models were adjusted for systolic blood pressure, HOMA-R, waist circumference, triglycerides, body mass index, and smoking habit. The serum total PUFA levels showed an inverse correlation with urinary albumin excretion rate (r = -0.248, P = .012). In conclusion, in type 2 diabetes mellitus patients, the serum fatty acids composition was independently related to endothelial function evaluated by serum ET-1. Saturated fatty acids were associated with endothelial dysfunction (high levels of ET-1), whereas PUFAs had a protective role in endothelial function.

Withdrawal of red meat from the usual diet reduces albuminuria and improves serum fatty acid profile in type 2 diabetes patients with macroalbuminuria.

BACKGROUND: Replacement of red meat in the diet with chicken has reduced the urinary albumin excretion rate (UAER) and serum cholesterol in microalbuminuric type 2 diabetes patients. The effects of withdrawing red meat are unknown in the more advanced stages of diabetic nephropathy. OBJECTIVE: Our objective was to assess the effects of replacing red meat in the usual diet (UD) with chicken (CD) and of consuming a lactovegetarian low-protein diet (LPD) on renal function, fatty acid, and lipid profile in macroalbuminuric type 2 diabetes patients. DESIGN: A crossover controlled trial was conducted in 17 type 2 diabetes patients with macroalbuminuria (24-h UAER > or = 200 microg/min). Each patient followed the UD, CD, and LPD in a random order for 4 wk. After each diet, glomerular filtration rate, UAER, serum fatty acid, lipid profile, glycemic control, anthropometric indexes, and blood pressure were measured. RESULTS: UAER [median CD: 269.4 (range: 111-1128) microg/min; LPD: 229.3 (76.6-999.3) microg/min; UD: 312.8 (223.7-1223.7) microg/min; P < 0.01] and mean (+/-SD) non-HDL cholesterol (CD: 3.92 +/- 0.99 mmol/L; LPD: 3.92 +/- 0.93 mmol/L; UD: 4.23 +/- 1.06 mmol/L; P = 0.042) were lower after CD and LPD than after UD. Compared with the UD, an increase in serum total polyunsaturated fatty acids was also observed (CD: 39.8 +/- 2.6%; LPD: 39.7 +/- 4.4%; UD: 37.3 +/- 3.1%; P = 0.029). CONCLUSION: In macroalbuminuric patients with type 2 diabetes, withdrawing red meat from the diet reduces the UAER.

Fatty acid composition of serum lipid fractions in type 2 diabetic patients with microalbuminuria.

OBJECTIVE: To determine the fatty acid composition of serum phospholipid, triglyceride, and cholesterol ester fractions and to analyze the lipid profile of microalbuminuric type 2 diabetic patients. RESEARCH DESIGN AND METHODS: A case-control study was conducted with 72 patients: 37 were normoalbuminuric (urinary albumin excretion rate [UAER] <20 microg/min), and 35 were microalbuminuric (UAER 20-200 microg/min). After 4 weeks of a standardized diet, the fatty acid composition of phospholipid, triglyceride, and cholesterol ester fractions was determined by gas chromatography. Total cholesterol and triglycerides were measured by enzymatic-colorimetric methods; cholesterol HDL by double precipitation with heparin, MnCl(2), and dextran sulfate; and apolipoprotein B by immunoturbidimetry. RESULTS: Microalbuminuric patients showed a lower proportion of polyunsaturated fatty acids (24.8 +/- 11.0%), especially of the n-6 family (21.7 +/- 10.5%), in triglyceride fraction than normoalbuminuric patients (34.1 +/- 11.3%, P = 0.001 and 31.4 +/- 11.5%, P < 0.001, respectively). Patients with microalbuminuria also presented higher levels of saturated fatty acids in triglyceride fraction (43.4 +/- 18.0% vs. 34.7 +/- 13.1%, P = 0.022). In the logistic regression analysis, only the proportion of polyunsaturated fatty acids in triglyceride fraction remained significantly associated with microalbuminuria (odds ratio [OR] 0.92, 95% CI 0.85-0.98, P = 0.019). Total cholesterol, HDL cholesterol, triglyceride, and apolipoprotein B levels were similar in normo- and microalbuminuric patients. CONCLUSION: Microalbuminuria in type 2 diabetic patients is associated with low polyunsaturated fatty acid contents in serum triglyceride fraction. This association may represent a risk factor for cardiovascular disease and may contribute to the progression of renal disease.