diabetes research and clinical practice 108 (2015) e1–e2
Contents available at ScienceDirect
Diabetes Research and Clinical Practice journ al h ome pa ge : www .elsevier.co m/lo cate/diabres
Letter to the Editor Comments on ‘‘Comparison of repaglinide and metformin versus metformin alone for type 2 diabetes: A meta-analysis of randomized controlled trials’’
studies are shown in Table 1. We do not know whether these studies will have any effects on the study’s conclusions. Second, heterogeneity (I2) between studies was greater than 82% which showed high variations between studies and could potentially bias the results of this study. However, heterogeneity among included studies was not further explored. In our opinion, the authors should perform subgroup and meta-regression analyses to identify sources of heterogeneity. For example, subgroup analyses can be conducted based on the trial duration, dosage of repaglinide or number of cases. Third, publication bias may distort results of the metaanalysis. It is not sufficient that publication bias was only assessed by visual examination of a funnel plot. Funnel plot symmetry should be further assessed by statistical tests (e.g., Egger’s linear regression test or Begg’s rank correlation test).
Dear Editors, We read with interest the article by Yin et al. [1] and believe this is a well-conducted meta-analysis comparing the clinical efficacy of repaglinide plus metformin with that of metformin alone in type 2 diabetes. While we agree with the overall conclusion that combination treatment resulted in better glycemic control than metformin treatment alone and that combination treatment was safe and not associated with increased hypoglycaemia, we have the following comments. First, 22 studies were included in the final analysis. According to their specific inclusion and exclusion criteria, we feel the authors may have missed another five randomized controlled trials [2–6]. The characteristics of these additional
Conflict of interest None.
Table 1 – Characteristics of included studies. Author (year)
Number (R + M/M)
Agea (R + M/M)
Sex (male/ female)
Trial Jadad duration score
Treatment
R+M
Outcomes
Adverse events (yes/no)
M Additional (mg/day) medication
R M (mg/day) (mg/day) Xue (2012) Shi (2012) Chen (2012) Zhou (2012) Dou (2013)
70 (34/36)
40–72/35–70
31/39
1.5–3
750–1500
750–1500
No
3 months
2
Yes
90 (44/46)
53/37
1.5–3
750–1500
750–1500
No
8 weeks
1
Yes
128 (64/64)
45.4 (9.2)/ 45.9 (9.5) 55.24 (9.68)
75/53
3
1500
1500
No
12 weeks
2
Yes
160 (80/80)
50.8
89/71
1.5–3
750–1500
750–1500
No
12 weeks
2
Yes
32/28
1.5–6
750–1500
750–1500
No
3 months
1
Yes
[2] [3] [4] [5] 60 (20/20/20) 51 [6]
Notes: R + M, repaglinide + metformin; M, metformin; (total cholesterol). a Presented in range or mean (standard deviation).
, HbA1c;
, FBG;
, PBG (postprandial blood sugar);
, TG (triglycerides);
, TC
e2
diabetes research and clinical practice 108 (2015) e1–e2
references
De-Qi Jianga,b Department of Pharmacy, Zhujiang Hospital of Southern Medical University, Guangzhou 510282, China b Department of Biopharmaceutical, Yulin Normal University, Yulin 537000, China (D.-Q. Jiang) a
[1] Yin J, Deng H, Qin S, Tang W, Zeng L, Zhou B. Comparison of repaglinide and metformin versus metformin alone for type 2 diabetes: a meta-analysis of randomized controlled trials. Diabetes Res Clin Pract 2014;105(3):e10–5. [2] Xue F. Clinical observations on therapeutic efficacy of repaglinide tablets and metformin in treatment of newdiagnosed type 2 diabetes mellitus. Yiyao Qianyan 2012;2(21):156–7. [3] Shi Y. The clinical efficacy of novonorm combined with metformin for 44 patients with type 2 diabetes mellitus. Cap Med 2012;3(6):29–30. [4] Chen EF. Investigation of the efficacy of novonorm combined with metformin on glycemic control in patients with type 2 diabetes mellitus. Strait Pharm J 2012;24(12): 231–3. [5] Zhou YX. Study of the clinical efficacy of novonorm combined with metformin for patients with type 2 diabetes mellitus. Yiyao Qianyan 2012;2(17):152. [6] Dou JA. The clinical study of repaglinide and metformin in the treatment of type 2 diabetes mellitus. Chin J Urban Rural Enterp Hyg 2013;28(5):18–9.
Ming-Xing Li Yong Wang* Department of Pharmacy, Zhujiang Hospital of Southern Medical University, Guangzhou 510282, China *
Corresponding author at: Department of Pharmacy, Zhujiang Hospital, Industrial Road No. 253, Haizhu District, Guangzhou 510282, Guangdong Province, China. Tel.: +86 20 61643555; fax: +86 20 84300639 E-mail address: [email protected] 19 December 2014 Available online 21 February 2015 http://dx.doi.org/10.1016/j.diabres.2015.02.004 0168-8227/# 2015 Elsevier Ireland Ltd. All rights reserved.
Contents available at ScienceDirect
Diabetes Research and Clinical Practice journ al h ome pa ge : www .elsevier.co m/lo cate/diabres
Letter to the Editor Comments on ‘‘Comparison of repaglinide and metformin versus metformin alone for type 2 diabetes: A meta-analysis of randomized controlled trials’’
studies are shown in Table 1. We do not know whether these studies will have any effects on the study’s conclusions. Second, heterogeneity (I2) between studies was greater than 82% which showed high variations between studies and could potentially bias the results of this study. However, heterogeneity among included studies was not further explored. In our opinion, the authors should perform subgroup and meta-regression analyses to identify sources of heterogeneity. For example, subgroup analyses can be conducted based on the trial duration, dosage of repaglinide or number of cases. Third, publication bias may distort results of the metaanalysis. It is not sufficient that publication bias was only assessed by visual examination of a funnel plot. Funnel plot symmetry should be further assessed by statistical tests (e.g., Egger’s linear regression test or Begg’s rank correlation test).
Dear Editors, We read with interest the article by Yin et al. [1] and believe this is a well-conducted meta-analysis comparing the clinical efficacy of repaglinide plus metformin with that of metformin alone in type 2 diabetes. While we agree with the overall conclusion that combination treatment resulted in better glycemic control than metformin treatment alone and that combination treatment was safe and not associated with increased hypoglycaemia, we have the following comments. First, 22 studies were included in the final analysis. According to their specific inclusion and exclusion criteria, we feel the authors may have missed another five randomized controlled trials [2–6]. The characteristics of these additional
Conflict of interest None.
Table 1 – Characteristics of included studies. Author (year)
Number (R + M/M)
Agea (R + M/M)
Sex (male/ female)
Trial Jadad duration score
Treatment
R+M
Outcomes
Adverse events (yes/no)
M Additional (mg/day) medication
R M (mg/day) (mg/day) Xue (2012) Shi (2012) Chen (2012) Zhou (2012) Dou (2013)
70 (34/36)
40–72/35–70
31/39
1.5–3
750–1500
750–1500
No
3 months
2
Yes
90 (44/46)
53/37
1.5–3
750–1500
750–1500
No
8 weeks
1
Yes
128 (64/64)
45.4 (9.2)/ 45.9 (9.5) 55.24 (9.68)
75/53
3
1500
1500
No
12 weeks
2
Yes
160 (80/80)
50.8
89/71
1.5–3
750–1500
750–1500
No
12 weeks
2
Yes
32/28
1.5–6
750–1500
750–1500
No
3 months
1
Yes
[2] [3] [4] [5] 60 (20/20/20) 51 [6]
Notes: R + M, repaglinide + metformin; M, metformin; (total cholesterol). a Presented in range or mean (standard deviation).
, HbA1c;
, FBG;
, PBG (postprandial blood sugar);
, TG (triglycerides);
, TC
e2
diabetes research and clinical practice 108 (2015) e1–e2
references
De-Qi Jianga,b Department of Pharmacy, Zhujiang Hospital of Southern Medical University, Guangzhou 510282, China b Department of Biopharmaceutical, Yulin Normal University, Yulin 537000, China (D.-Q. Jiang) a
[1] Yin J, Deng H, Qin S, Tang W, Zeng L, Zhou B. Comparison of repaglinide and metformin versus metformin alone for type 2 diabetes: a meta-analysis of randomized controlled trials. Diabetes Res Clin Pract 2014;105(3):e10–5. [2] Xue F. Clinical observations on therapeutic efficacy of repaglinide tablets and metformin in treatment of newdiagnosed type 2 diabetes mellitus. Yiyao Qianyan 2012;2(21):156–7. [3] Shi Y. The clinical efficacy of novonorm combined with metformin for 44 patients with type 2 diabetes mellitus. Cap Med 2012;3(6):29–30. [4] Chen EF. Investigation of the efficacy of novonorm combined with metformin on glycemic control in patients with type 2 diabetes mellitus. Strait Pharm J 2012;24(12): 231–3. [5] Zhou YX. Study of the clinical efficacy of novonorm combined with metformin for patients with type 2 diabetes mellitus. Yiyao Qianyan 2012;2(17):152. [6] Dou JA. The clinical study of repaglinide and metformin in the treatment of type 2 diabetes mellitus. Chin J Urban Rural Enterp Hyg 2013;28(5):18–9.
Ming-Xing Li Yong Wang* Department of Pharmacy, Zhujiang Hospital of Southern Medical University, Guangzhou 510282, China *
Corresponding author at: Department of Pharmacy, Zhujiang Hospital, Industrial Road No. 253, Haizhu District, Guangzhou 510282, Guangdong Province, China. Tel.: +86 20 61643555; fax: +86 20 84300639 E-mail address: [email protected] 19 December 2014 Available online 21 February 2015 http://dx.doi.org/10.1016/j.diabres.2015.02.004 0168-8227/# 2015 Elsevier Ireland Ltd. All rights reserved.
