Figure 1
Flowchart of the detailed procedure for the inclusion or exclusion of selected studies.
Table 1
Study characteristics of the published studies included in the meta-analysis.
| AUTHOR | PUBLICATION YEAR | REGION | NUMBER | LEPTIN | DETAILS | |||
|---|---|---|---|---|---|---|---|---|
| CASE | CONTROL | CASE | CONTROL | CASE | CONTROL | |||
| Toth MJ | 1997 | USA | 18 | 46 | 5.1 ± 4.2 | 6.8 ± 4.4 | Eighteen patients (aged 71 ± 6 years) with HF were recruited. Ten patients with documented coronary artery disease and eight patients with dilated cardiomyopathy unrelated to coronary artery disease. | Forty-six healthy elderly subjects (aged 66 ± 6 years) served as a control group. |
| Leyva F | 1998 | Germany | 25 | 18 | 8.12 ± 1.3 | 4.48 ± 0.7 | The study group consisted of 25 patients with congestive HF. Chronic HF was secondary to coronary heart disease in 13 and to idiopathic dilated cardiomyopathy in 12. | Healthy controls were matched to congestive HF patients for age, sex, and total body fat. |
| Murdoch DR | 1999 | UK | 51 | 26 | 10.82 ± 5.86 | 18.3 ± 3.5 | The study group consisted of 51 patients, aged 52 to 83 years, with stable chronic HF of more than 3 months duration. The primary cause of HF was coronary artery disease in 48 patients and regurgitant valve disease in 3 patients. | The control group consisted of 26 matched healthy volunteers, aged 30 to 76 years. |
| El-Bindary EM | 2001 | Egypt | 80 | 20 | 16.94 ± 6.33 | 12.25 ± 3.9 | The study group consisted of 47 patients (aged 47 ± 4 years) with chronic HF. | The control group consisted of 20 aged- and sex-matched healthy volunteers. |
| Doehner W | 2001 | Germany | 47 | 21 | 7.6 ± 0.7 | 4.8 ± 0.7 | The study group consisted of 47 patients (aged 61 ± 2 years) with chronic HF due to ischemic heart disease (n = 28) or idiopathic dilated cardiomyopathy (n = 19). | The control group consisted of 21 healthy subjects (aged 59 ± 3 years) of similar age. |
| Schulze PC | 2003 | Germany | 53 | 11 | 7.72 ± 0.9 | 6.36 ± 1.35 | Patients (aged 71 ± 6 years) with chronic HF as a result of dilated cardiomyopathy or ischemic heart disease were included in this study. | A total of 11 age-matched patients (aged 61 ± 4 years), who were admitted with non-specific chest pain for the exclusion of coronary artery disease, served as controls. |
| McEntegart MB | 2007 | UK | 30 | 7 | 11.57 ± 4.98 | 11.1 ± 4.225 | Patients (aged 56.6 ± 1.3 years) with HF as a result of coronary artery disease. | Healthy controls (aged 60.4 ± 4.0 years) were recruited from patient companions at the cardiology clinics. In addition to age-matching a lifestyle history was taken to activity-match healthy controls to the patients. |
| Fernandes F | 2007 | Brazil | 14 | 30 | 1.4 ± 0.8 | 8.1 ± 7.8 | Patients (aged 47.8 ± 9.1 years) with HF as a result of Chagas’ disease. | The control group consisted of 30 healthy individuals (aged 43.9 ± 5.9 years). |
| Patel JV | 2007 | UK | 101 | 110 | 7.90 ± 3.42 | 6.30 ± 2.67 | The study group consisted of South Asian and European Caucasian descent patients with mild to moderate chronic HF. | Age, gender and ethnically matched controls were recruited from relatives of patients, healthy hospital staff, and local community groups. |
| Sierra-Johnson J | 2008 | USA | 135 | 106 | 13.2 ± 12 | 7.6 ± 6 | One hundred thirty-five consecutively eligible white patients (aged 55.8 ± 11 years) with a diagnosis of stable noncachectic systolic HF were recruited. The etiology of HF was ischemic or nonischemic dilated cardiomyopathy. | The control group consisted of 104 healthy individuals (aged 53.8 ± 15 years). |
| Straburzyńska-Migaj E | 2010 | Poland | 41 | 8 | 9.2 ± 7.5 | 2.9 ± 1.2 | The study group consisted of 41 patients (aged 50.1 ± 9.3 years) with HF. Coronary artery disease was diagnosed in 16 patients and dilated cardiomyopathy in the remaining 25 patients. | The control group consisted of eight healthy volunteers (aged 43.6 ± 14.7 years) of a similar age and gender distribution to the patients with HF. |
| Schulze PCMP | 2011 | USA | 80 | 21 | 8.67 ± 5.45 | 3.7 ± 2.7 | A total of 44 patients (aged 61 ± 12 years) with acute decompensated HF, and 26 patients (aged 63 ± 12 years) with chronic HF were enrolled in this study. | The control group consisted of 21 healthy individuals (aged 57 ± 13 years). |
| Bobbert P | 2012 | Germany | 104 | 16 | 13.38 ± 16.53 | 7.34 ± 5.7 | A total of 52 patients (aged 48.3 ± 13.3 years) with non-ischaemic dilated cardiomyopathy, and 52 patients (aged 49.3 ± 14.3 years) with inflammatory cardiomyopathy were enrolled in this study. | The control group was comprised of patients (aged 40.4 ± 7.7 years) admitted to the hospital for evaluation of suspected cardiomyopathy, in whom the diagnostic work-up finally revealed that their complaints were noncardiac in origin. |
| Karayannis G | 2013 | Greece | 57 | 64 | 9 ± 10.3 | 8.7 ± 8.7 | The study group consisted of 57 consecutive patients (aged 68 ± 12 years) hospitalized for decompensated HF. | The control group was comprised of 64 age- and sex-matched asymptomatic individuals (aged 64 ± 11 years). |
| Loncar G | 2013 | Serbia | 73 | 20 | 7.3 ± 6.7 | 5.9 ± 3.2 | The study group consisted of 73 males (aged 68 ± 7 years) with chronic HF due to ischaemic or idiopathic dilated cardiomyopathy. | The control group consisted of 20 male volunteers (aged 67 ± 7 years), without the history of any chronic disease and without any regular medication regimen. |
| Faxen UL | 2017 | Sweden | 163 | 71 | 19.17 ± 26.02 | 10.8 ± 2.6 | The study group consisted of 163 patients with HF. | The control group consisted of 71 individuals without self-reported cardiovascular disease or known hypertension. |
| Shiina Y | 2018 | Japan | 46 | 12 | 10.1 ± 8.14 | 10.3 ± 3.5 | The study group consisted of 46 patients (aged 32.1 ± 7.4 years) with HF due to congenital heart disease. | Twelve age-matched healthy subjects (aged 31.5 ± 7.2 years), all of whom were medical staff at our hospital and were enrolled as controls. |
| Dabarian AL | 2019 | Brazil | 31 | 15 | 5.28 ± 4.45 | 5.61 ± 5.96 | A total of 15 patients (aged 42.67 ± 6.72 years) with Chagas heart disease, and 16 patients (aged 46.2 ± 8.12 years) with idiopathic dilated cardiomyopathy were enrolled in this study. | Healthy controls (aged 48.3 ± 7.48 years) were matched to HF patients for age, sex, and body mass index. |
[i] HF, heart failure.
Figure 2
Forest plots of leptin level in patients with heart failure compared to healthy individuals. Diamond represents the pooled SMDs at 95% CI. SMD, standardized mean difference; CI, confidence interval.
Figure 3
The sensitivity analysis results of leptin level in patients with heart failure compared to healthy individuals.