You will be shown the abstract of a medical clinical trial report. Your task is to extract all the findings from this report into a JSON array. Each finding should contain the following five elements:

- Intervention: The medical intervention being tested. This should be a text span copied from the input passage.
- Comparator: The baseline against which the intervention is being evaluated. This should be a text span copied from the input passage. If no comparator is reported, set to `null`.
- Outcome: The medical outcome whose effect is being measured. This should be a text span copied from the input passage.
- Effect: The effect of the intervention on the outcome, relative to the comparator. The effect should be one of the following three values: ("significantly increased", "significantly decreased", "no significant difference").
- Evidence: The evidence for the effect. This should be a text span copied from the input passage.

Please format your output as a JSON array. Each entry in the output should be an array containing the 5 elements listed above, in the following order: [<intervention>, <comparator>, <outcome>, <effect>, <evidence>].

For example, an output with two findings might read:
```
[["aspirin", "placebo", "headache severity", "significantly decreased", "Mean headache severity was significantly decreased in the aspirin group compared to the placebo group (p < 0.05)."], ["aspirin", "placebo", "weight loss", "no significant difference", "We did not observe any difference in weight loss between the group given aspirin relative to the control group"]]
```

There are 4 finding(s) in the abstract below. Please extract them. Output only the JSON array with these 4 findings. Do not include any additional text.

Abstract:
ABSTRACT.BACKGROUND: Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers are renoprotective but both may increase serum potassium concentrations in patients with chronic kidney disease (CKD). The proportion of affected patients, the optimum follow-up period and whether there are differences between drugs in the development of this complication remain to be ascertained.

ABSTRACT.METHODS: In a randomized, double-blind, phase IV, controlled, crossover study we recruited 30 patients with stage 3 CKD under restrictive eligibility criteria and strict dietary control. With the exception of withdrawals, each patient was treated with olmesartan and enalapril separately for 3 months each, with a 1-week wash-out period between treatments. Patients were clinically assessed on 10 occasions via measurements of serum and urine samples. We used the Cochran–Mantel–Haenszel statistics for comparison of categorical data between groups. Comparisons were also made using independent two-sample t-tests and Welch's t-test. Analysis of variance (ANOVA) was performed when necessary. We used either a Mann–Whitney or Kruskal-Wallis test if the distribution was not normal or the variance not homogeneous.

ABSTRACT.RESULTS: Enalapril and olmesartan increased serum potassium levels similarly (0.3 mmol/L and 0.24 mmol/L respectively). The percentage of patients presenting hyperkalemia higher than 5 mmol/L did not differ between treatments: 37% for olmesartan and 40% for enalapril. The mean e-GFR ranged 46.3 to 48.59 ml/mint/1.73 m2 in those treated with olmesartan and 46.8 to 48.3 ml/mint/1.73 m2 in those with enalapril and remained unchanged at the end of the study. The decreases in microalbuminuria were also similar (23% in olmesartan and 29% in enalapril patients) in the 4 weeks time point. The percentage of patients presenting hyperkalemia, even after a two month period, did not differ between treatments. There were no appreciable changes in sodium and potassium urinary excretion.

ABSTRACT.CONCLUSIONS: Disturbances in potassium balance upon treatment with either olmesartan or enalapril are frequent and without differences between groups. The follow-up of these patients should include control of potassium levels, at least after the first week and the first and second month after initiating treatment.

ABSTRACT.TRIAL REGISTRATION: The trial EudraCT "2008-002191-98".

Findings:
[["Enalapril", "Olmesartan", "Glomerular filtration rate increase ", "no significant difference", "The mean e-GFR ranged 46.3 to 48.59 ml/mint/1.73 m2 in those treated with olmesartan and 46.8 to 48.3 ml/mint/1.73 m2 in those with enalapril and remained unchanged at the end of the study."], ["Enalapril", "Olmesartan", "Microalbuminuria decrease", "no significant difference", "The decreases in microalbuminuria were also similar (23% in olmesartan and 29% in enalapril patients) in the 4 weeks time point."], ["Enalapril", "Olmesartan", "Hyperkalemia higher than 5 mmol/L", "no significant difference", "The percentage of patients presenting hyperkalemia higher than 5 mmol/L did not differ between treatments: 37% for olmesartan and 40% for enalapril."], ["Enalapril", "Olmesartan", "Urinary potassium", "no significant difference", "There were no appreciable changes in sodium and potassium urinary excretion."]]