Regular consumption of both vitamin D- and calcium- and vitamin D-fortified yogurt drink is equally accompanied by lowered blood lipoprotein (a) and elevated apoprotein A1 in subjects with type 2 diabetes: a randomized clinical trial.

OBJECTIVE: Cardiovascular disease (CVD) is the major morbidity and cause of death in diabetic subjects. Observational studies have shown the association of low vitamin D status with poor glycemic control, atherogenic lipid profile, and CVD. However, the possible link between circulating 25-hydroxycholecalciferol and apoproteins (Apo A1 and B) and the atherogenic lipoprotein (a) [Lp(a)] has not been documented to date. METHODS: Ninety subjects with type 2 diabetes (T2D) aged 30-60 years from both sexes were randomly allocated to one of the 3 groups to receive 2 bottles a day of either (1) plain doogh (PD; containing 150 mg calcium and no detectable vitamin D/250 mL); (2) vitamin D-fortified doogh (DD; containing 150 mg calcium and 500 IU vitamin D/250 mL); or (3) calcium- and vitamin D-fortified doogh (CDD; containing 250 mg calcium and 500 IU vitamin D/250 mL) for 12 weeks. Anthropometric, dietary, and laboratory assessments, including Apo A1, Apo B, and Lp(a), were done. RESULTS: Improvement of vitamin D status in DD and CDD groups, compared to PD, resulted in a significant increase in Apo A1 (mean changes 0.22 ± 0.38, 0.20 ± 0.27 and 0.01 ± 0.35 g/L, respectively, p = 0.047) and a significant decrease in serum Lp(a) (mean changes -0.08 ± 0.30, -0.08 ± 0.31, and 0.14 ± 0.25 µmol/L, respectively, p = 0.011). There was no significant difference between DD and CDD groups. Serum Apo B did not change significantly in any of the groups. CONCLUSIONS: Significant amelioration of serum Apo A1 and Lp(a) following improvement of vitamin D status in T2D subjects may have preventive implications against long-term diabetic complications, notably CVD. This trial was registered at ClinicalTrials.gov as NTC01229891.

Regular consumption of vitamin D-fortified yogurt drink (Doogh) improved endothelial biomarkers in subjects with type 2 diabetes: a randomized double-blind clinical trial.

BACKGROUND: Endothelial dysfunction has been proposed as the underlying cause of diabetic angiopathy that eventually leads to cardiovascular disease, the major cause of death in diabetes. We recently demonstrated the ameliorating effect of regular vitamin D intake on the glycemic status of patients with type 2 diabetes (T2D). In this study, the effects of improvement of vitamin D status on glycemic status, lipid profile and endothelial biomarkers in T2D subjects were investigated. METHODS: Subjects with T2D were randomly allocated to one of the two groups to receive either plain yogurt drink (PYD; containing 170 mg calcium and no vitamin D/250 mL, n1 = 50) or vitamin D3-fortified yogurt drink (FYD; containing 170 mg calcium and 500 IU/250 mL, n2 = 50) twice a day for 12 weeks. Anthropometric measures, glycemic status, lipid profile, body fat mass (FM) and endothelial biomarkers including serum endothelin-1, E-selectin and matrix metalloproteinase (MMP)-9 were evaluated at the beginning and after the 12-week intervention period. RESULTS: The intervention resulted in a significant improvement in fasting glucose, the Quantitative Insulin Check Index (QUICKI), glycated hemoglobin (HbA1c), triacylglycerols, high-density lipoprotein cholesterol (HDL-C), endothelin-1, E-selectin and MMP-9 in FYD compared to PYD (P < 0.05, for all). Interestingly, difference in changes of endothelin-1, E-selectin and MMP-9 concentrations in FYD compared to PYD (-0.35 ± 0.63 versus -0.03 ± 0.55, P = 0.028; -3.8 ± 7.3 versus 0.95 ± 8.3, P = 0.003 and -2.3 ± 3.7 versus 0.44 ± 7.1 ng/mL, respectively, P < 0.05 for all), even after controlling for changes of QUICKI, FM and waist circumference, remained significant for endothelin-1 and MMP-9 (P = 0.009 and P = 0.005, respectively) but disappeared for E-selectin (P = 0.092). On the contrary, after controlling for serum 25(OH)D, the differences disappeared for endothelin-1(P = 0.066) and MMP-9 (P = 0.277) but still remained significant for E-selectin (P = 0.011). CONCLUSIONS: Ameliorated vitamin D status was accompanied by improved glycemic status, lipid profile and endothelial biomarkers in T2D subjects. Our findings suggest both direct and indirect ameliorating effects of vitamin D on the endothelial biomarkers. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01236846.

Regular daily intake of black tea improves oxidative stress biomarkers and decreases serum C-reactive protein levels in type 2 diabetic patients.

BACKGROUND: This study was undertaken to evaluate the possible effects of different daily doses of black tea intake on certain oxidative stress, inflammatory and metabolic biomarkers in patients with type 2 diabetes mellitus (T2DM). METHODS: Forty-six patients with known T2DM were randomly assigned either to the test (n = 23, 57.0 +/- 7.9 years) or the control (n = 23, 55.4 +/- 8.3 years) group. Following a one-week 'run-in' period, the test group received 150, 300, 450 and 600 ml of black tea extract (BTE) during the weeks 1, 2, 3 and 4, respectively. The control group received 150 ml BTE a day throughout the intervention period. Dietary, anthropometric and biochemical assessments were performed at the end of each week. FINDINGS: Serum total antioxidant capacity was enhanced similarly in both test and control groups. However, daily intake of 2 cups of BTE by the test group showed a suppressing effect on serum malondialdehyde. Serum C-reactive protein significantly decreased and glutathione levels increased following the intake of 4 cups (600 ml) of BTE a day. CONCLUSION: Regular intake of BTE had anti-oxidative and anti-inflammatory effects in patients with T2DM. These findings may, to some extent, explain the mechanisms underlying the protective effects of drinking tea against cardiovascular disease.

The opposite associations of lycopene and body fat mass with humoral immunity in type 2 diabetes mellitus: a possible role in atherogenesis.

This study examined the possible effects of lycopene at physiological dosage and body fat mass on the humoral immune response in patients with type 2 diabetes mellitus (T2DM). A total of 35 patients with Typ2 diabetes mellitus from both sexes aged 54+/-9 yrs from the Iranian Diabetes Society were introduced into a double blind placebo controlled clinical trial conducted for 2 months. After a 2-week lycopene free diet washout period, patients were allocated to either lycopene supplementation group (10mg/d) (n=16) or placebo age- and sex matched group (n=19) for 8 weeks. Patients were instructed to keep their diets and physical activities as unchanged as possible. Lycopene supplements increased serum lycopene levels (p<0.001). While intake of dietary energy and nutrients did not change in either groups, the ratio of total antioxidant capacity to malondialdehyde increased significantly in the lycopene group (p=0.007). There was an inverse correlation between serum levels of lycopene and those of IgG (r= -0.338, p=0.008). On the contrary, changes of serum levels of lycopene directly correlated with those of IgM (r=0.466, p=0.005). Interestingly, changes of the amount of fat mass correlated directly with those of serum IgG (r=0.415, p=0.044) but inversely with of serum IgM (r= -0.469, p=0.021). While truncal fat might promote adaptive humoral immunity, lycopene probably by inhibiting MDA-LDL formation might attenuate T cell dependent adaptive (pro-atherogenic) humoral immune response. These findings may have preventive implications in long term diabetic complications, notably atherogenesis.

Selective microbiologic effects of tea extract on certain antibiotics against Escherichia coli in vitro.

OBJECTIVES: This study evaluated the microbiologic effects of black tea, compared to green tea, alone and in conjunction with selected antibiotics against Escherichia coli, the common cause of intestinal and urinary tract infections. DESIGN: This study was an in vitro evaluation of antibacterial effects of tea extracts. METHODS: Black and green tea extracts were analyzed by using high-performance liquid chromatography to compare their major polyphenol profiles. Different concentrations of the extracts or gallic acid (GA), the phenolic compound found with high concentration in the black tea extract, were employed for bacterial sensitivity tests, using pour plate and disc diffusion methods. The latter was used to evaluate the interactions between the extracts and certain anti-E. coli antibiotics. RESULTS: GA in black tea extract and epigallocatechin and epigallocatechin gallate in green tea extract are present in the highest concentrations, respectively. At concentrations of 25 mg/mL, both black and green teas after 5 and 7 hours completely inhibited E. coli growth. GA at concentrations of 5, 10, and 25 microg/mL after 7, 5 and 3 hrs, respectively, inhibited bacterial growth. Both black and green tea extracts had either synergistic or antagonistic effects at different concentrations on selected antibiotics, while GA showed a synergistic effect with all the antibiotics tested in a dose-dependent manner. The effect was more prominent with amikacin and sulfamethoxazole. CONCLUSIONS: The microbiologic effects of both black tea and green tea extracts on certain antibiotics against E. coli may vary, depending on the type of the tea extract (i.e., black vs. green), the amount of the extract, and the antibiotic being used.