Study characteristics
The general characteristics of the 7 qualified articles (9 dataset) are
illustrated in Table 1. Selected eligible trials enrolled 1786
participants with age ranging from 18 to 65 years old and were conducted
on both genders, except for one trial that exclusively included women
[25]. A number of subjects in intervention and control groups were
896 and 890, respectively. Participants were patients with overweight
and obesity[20, 22-26], untreated type 2 diabetes and untreated
hypertension[20], type 2 DM treated with oral antidiabetic agents
(metformin alone or in combination with sulfonylureas)[21, 22],
metabolic syndrome[21-23], hypertension treated with drug[22,
24], coronary heart disease concomitant cardiac dysfunction [22],
hypercholesterolemia [20, 24] , PCOS [25], NAFLD [26]. All
selected studies used a parallel design including a control group.
Duration of orlistat therapy varied from 3 to 6 months. Daily prescribed
dosage of orlistat varied between 120mg three times a day (tid) [20,
22-26] and 360mg/dl [21]. Items that participants received with
orlistat during the study include: low calorie diet[20, 21], fat
restricted diet and physical activity[22], low calorie/low fat diet
and other medication[23-25] and in one study they didn’t take
anything with orlistat[26]. The quality assessment results of the
articles are shown in Fig 2.
Effect of orlistat on serum uric acid levels
7 qualified studies (9 dataset) including a total of 1786 subjects,
reported serum uric acid as their outcome. Combining their findings
based on random-effects model, we found that serum uric acid was
significantly reduced in orlistat group compared to the control
(Difference in means: -17.661μmol, 95% CI: -31.615 to -3.707, P=0.01)
(Fig3), including no significant heterogeneity between studies
(\(I^{2}=25.119\%\), Q-value=10.68) .We removed one study and repeated
the analysis after excluding the study while the findings did not
change. Based on subgroup analysis includes intervention period (3month
and 6 month), sample size (< 100 and ≥ 100 participants),
health status (metabolic syndrome, hypercholesterolemia, PCOS and NAFLD)
were responsible, at least to some extent, for between-study
heterogeneity.