Table 1.
Characteristics of included studies in the meta-analysis.
| First author | Year, country | Subjects | Participants | Gender | Mean Age | Mean BMI | Design | Supplement | Comparator | Dose (mg/d) | Duration (week) | Baseline mean (SBP/DBP) | Medications | Adjustments | Main results | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Int | Con | Int | Con | Int | Con | Int | Con | ||||||||||||
| Nasiri et al. | 2021, Iran | Overweight | 21 | 21 | B | 34.86 | 34.67 | 27.78 | 27.57 | RDBPC | ALA + probiotic | Probiotic | 600 | 16 | (140.40/91.27) | (140.17/91.28) | – | – | Significant reduction in SBP and DBP in the ALA group |
| Bobe et al. | 2020, United States | Overweight | 31 | 33 | B | 38 | 40 | 34.8 | 34.4 | RDBPC | (R)- ALA | Placebo (Placebo type unclear) | 600 | 24 | (127/75) | (125/74) | – | – | No differences in SBP and DBP between groups |
| Mendoza-Núñez et al. | 2019, Mexico | T2DM | 42 | 38 | B | 63 | 64 | 28.69 | 28.96 | RCT | ALA | Placebo (Microcrystalline cellulose) | 600 | 24 | (124/78) | (126/77) | Glibenclamide/metformin | – | No significant difference in SBP and DBP between groups |
| Gosselin et al. | 2019, United States | pre-diabetics | 12 | 12 | B | 47.1 | 47.1 | 33.4 | 33.4 | RDBPC | ALA | Placebo (cellulose) | 600 | 4 | (130.2/87) | (130.2/87) | – | – | No significant difference in SBP and DBP between groups |
| Mohammadi et al. | 2018, Iran | Stroke | 33 | 34 | B | 62.33 | 64.23 | – | – | RDBPC | ALA | Placebo (wheat flour) | 600 | 12 | (133.18/84.24) | (132.94/86.02) | – | Baseline values, energy intake, and weight | Significant reduction in SBP and DBP in the ALA group compared with the placebo group |
| Raffaele et al. | 2016, Italy | TCM | 22 | 21 | F | 63.7 | 63.9 | 27 | 27.6 | RDBPC | ALA | Placebo | 600 | 48 | (122/81.3) | (123/82.2) | Beta-blockers, ACEi/ARB, Aspirin, and Statin | – | No significant change in SBP and DBP between groups |
| Gargari et al. | 2015, Iran | RA | 33 | 32 | F | 36.09 | 38.28 | 29 | 29.02 | RDBPC | ALA | Placebo (Maltodextrin) | 1,200 | 8 | (121.59/117.65) | (77.04/72.69) | – | Baseline values | Significant reduction in SBP and DBP between groups |
| Mohammadi et al. | 2015, Iran | SCI | 28 | 30 | M | 39 | 36.8 | 27.77 | 28.02 | RDBPC | ALA | Placebo (wheat flour) | 600 | 12 | (126.43/123.50) | (87.85/82.50) | – | Baseline covariates and changes in weight | Significant reduction in SBP and DBP between groups |
| Koh et al. | 2011, Korea | Obesity | 82 | 73 | B | 41.4 | 40.7 | 33.3 | 33.1 | RDBPC | ALA | Placebo (lactose and cellulose) | 1,800 | 20 | (137.48/84.67) | (131.95/79.95) | Antihypertensive/hypoglycemic agents/lipid-lowering medications | – | No significant difference in SBP and DBP between groups |
| Lukaszuk et al. | 2009, United States | T2DM | 13 | 7 | B | 56 | 53.14 | 33.8 | 33.3 | RDBPC | R- ALA | Placebo (Microcellulose) | 600 | 13 | (127.6/78.3) | (123.9/76.3) | Anti-diabetic medication and/or insulin, anti-hypertensives, anti-hyperlipidemic, anti-inflammatories, and… | – | No significant differences in blood pressure between the groups |
| Ziegler et al. | 1997, Germany | NIDDM | 29 | 27 | B | 57.9 | 58.6 | – | – | RDBPC | ALA | Placebo (Placebo type unclear) | 800 | 16 | (144/81.4) | (144/85.3) | Insulin treatment/Oral anti-diabetic agents | Baseline values | No significant difference in SBP and DBP between groups |
ALA, alpha-lipoic acid; BMI, body mass index; DBP, diastolic blood pressure; SCI, spinal cord injury; TCM, Takotsubo cardiomyopathy; RA, Rheumatoid arthritis; RDBPC, randomized double-blind placebo-controlled; RCT, randomized controlled trial; T2DM, SBP, systolic blood pressure; Type 2 Diabetes mellitus, NIDDM, Non-insulin-dependent diabetes mellitus; M, male; F, female; B, both; Int, intervention; Con, control.