Nutrition and health

Objectives:
What is the impact of antioxidants (N-acetylcysteine (NAC), polyunsaturated fatty acids (PUFAs) and vitamins) on incidence of postoperative atrial fibrillation (POAF) and duration of length of hospital stay?

Study design:
This review article included 23 RCTs that reported outcomes of 4278 patients undergoing cardiac surgery.
A total of 10 RCTs with 1,026 patients (513 cases were allocated to the NAC and 513 cases to the control group, with a mean age of 63.2 years and 76.8% being males), 8 RCTs with 2,687 patients (with a mean age of 64.17 years and 77.6% being males), and 5 RCTs with 565 patients (with a mean age of 65.17 years and 73.6% being males) investigated the effect of NAC, PUFA and antioxidant vitamins on POAF, respectively.

There was no publication bias.

Results and conclusions:
The investigators found pooled effects estimates on postoperative atrial fibrillation showed a significant reduction after:
NAC [OR = 0.56, 95% CI = 0.40-0.77, p 0.001, I2 = 15%, p = 0.3];
PUFA [OR = 0.84, 95% CI = 0.71-0.99, p = 0.03] and;
Vitamin C treatment [OR = 0.50, 95% CI = 0.27-0.91, p = 0.02, I2 = 50%].

The investigators found hospital length of stay was not significant reduced after NAC therapy [SMD = 0.082, 95% CI = -0.09 to 0.25, p = 0.3, I2 = 0.0%, p = 0.7], but could be significant decreased with PUFA [SMD = -0.185, 95% CI = -0.35 to -0.018, p = 0.03, I2 = 11%, p = 0.3] and vitamin C [SMD = -0.325, 95% CI = -0.50 to -0.14, p 0.01, I2 = 60.4%, p = 0.056].
Significant because the p-values were less than the p-value of 0.05.

The investigators concluded perioperative antioxidant supplementations with N-acetylcysteine, polyunsaturated fatty acids and vitamin C prevent atrial fibrillation after cardiac surgery. Moreover, polyunsaturated fatty acids and vitamin C are capable to reduce hospital stay, whereas N-acetylcysteine lacks this capacity.

Original title:
Antioxidant supplementations for prevention of atrial fibrillation after cardiac surgery: an updated comprehensive systematic review and meta-analysis of 23 randomized controlled trials by Ali-Hassan-Sayegha S, Mirhosseinia SJ, […], Liakopoulose OJ.

Link:
http://icvts.oxfordjournals.org/content/early/2014/02/19/icvts.ivu020.long

Additional information of El Mondo:
Find more studies on cardiovascular diseases, antioxidants, NAC, PUFA, vitamin C and p-value of 0.05/95% CI right here. 

Objectives:
Does niacine supplementation reduce blood lipids levels in patients with type 2 diabetes mellitus?

Study design:
This review article included randomized controlled trials.

The meta-analysis showed the absence of publication bias and any dose-response relations between niacin and effect size.

There was a significant heterogeneity for the impact of niacin on LDL cholesterol and fasting plasma glucose.

Results and conclusions:
The investigators found niacin supplementation significantly increased HDL cholesterol with 0.27 mmol/L [95% CI = 0.24 to 0.30, p 0.001] in patients with type 2 diabetes mellitus.

The investigators found niacin supplementation significantly reduced LDL cholesterol with 0.250 mmol/L [95% CI = -0.47 to -0.03, p 0.05] in patients with type 2 diabetes mellitus.

The investigators found niacin supplementation significantly reduced triglycerides with 0.39 mmol/L [95% CI = -0.43 to -0.34, p 0.001] in patients with type 2 diabetes mellitus.

The investigators found niacin supplementation significantly increased fasting plasma glucose with 0.085 mmol/L [95% CI = 0.029 to 0.141, p 0.05] compared with controls in patients with long term treatment.

The investigators concluded niacin alone or in combination improves lipid abnormalities in patients with type 2 diabetes mellitus, but requires monitoring of glucose in long term treatment.

Original title:
Effect of niacin on lipids and glucose in patients with type 2 diabetes: A meta-analysis of randomized, controlled clinical trials by Ding Y, Li Y and Wen A.

Link:
http://www.ncbi.nlm.nih.gov/pubmed/25306426

Additional information of El Mondo:
Find more information on niacin (vitamin B3) and diabetes.

Objectives:
Observational studies suggest an association between dietary fiber intake and risk of type 2 diabetes, but the results are inconclusive. Therefore, this review article (meta-analysis) has been conducted.

Does dietary fiber intake reduce risk of type 2 diabetes?

Study design:
This review article included 17 prospective cohort studies of dietary fiber intake and risk of type 2 diabetes involving 19,033 cases and 488,293 participants.

Results and conclusions:
The investigators found total dietary fiber intake significantly reduced risk of type 2 diabetes with 19% [combined RR = 0.81, 95% CI = 0.73-0.90].

The investigators found dietary cereal fiber intake significantly reduced risk of type 2 diabetes with 23% [combined RR = 0.77, 95% CI = 0.69-0.85].

The investigators found dietary fruit fiber intake significantly reduced risk of type 2 diabetes with 6% [combined RR = 0.94, 95% CI = 0.88-0.99].

The investigators found dietary insoluble fiber intake significantly reduced risk of type 2 diabetes with 25% [combined RR = 0.75, 95% CI = 0.63-0.89].

The investigators found a nonlinear relationship of total dietary fiber intake with risk of type 2 diabetes [p for nonlinearity 0.01].

The investigators found dietary fiber intake of 15g per day non-significantly reduced risk of type 2 diabetes with 2% [combined RR = 0.98, 95% CI = 0.90-1.06].

The investigators found dietary fiber intake of 20g per day non-significantly reduced risk of type 2 diabetes with 3% [combined RR = 0.97, 95% CI = 0.87-1.07].

The investigators found dietary fiber intake of 25g per day significantly reduced risk of type 2 diabetes with 11% [combined RR = 0.89, 95% CI = 0.80-0.99].

The investigators found dietary fiber intake of 30g per day significantly reduced risk of type 2 diabetes with 24% [combined RR = 0.76, 95% CI = 0.65-0.88].

The investigators found dietary fiber intake of 35g per day significantly reduced risk of type 2 diabetes with 34% [combined RR = 0.66, 95% CI = 0.53-0.82].

The investigators found that the risk of type 2 diabetes decreased by 6% [combined RR = 0.94, 95% CI = 0.93-0.96] for 2 g/day increment in cereal fiber intake.

The investigators concluded that the intakes of dietary fiber, at least 25g total dietary fiber intake per day reduce risk of type 2 diabetes.

Original title:
Dietary fiber intake and risk of type 2 diabetes: a dose–response analysis of prospective studies by Yao B, Fang H, […], Zhao Y.

Link:
http://link.springer.com/article/10.1007/s10654-013-9876-x

Additional information of El Mondo:
Find more information on fiber and type 2 diabetes right here.