L-methionine

Epidemiological data

Administrative data

Endpoint:

epidemiological data

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Data source

Reference

Title:

Methionine-loading test: evaluation of adverse effects and safety in an epidemiological study

Author:

Krupkova-Meixnerova L, Vesela K, Vıtova A, Janosıkova B, Andel M, Kozich V

Year:

2002

Bibliographic source:

Clin Nutr. 2002;21:151–6.

Materials and methods

Test material

Test material information

Constituent 1

Reference substance name:

L-methionine

EC Number:

200-562-9

EC Name:

L-methionine

Cas Number:

63-68-3

Molecular formula:

C5H11NO2S

IUPAC Name:

L-methionine

Details on test material:

- Name of test material (as cited in study report): L-methionine
- Supplier: Ajinomoto Co., Inc., Japan;
- Lot/batch No.: five different lots were utilized between 1998 and 2000

Method

Details on study design:

HYPOTHESIS TESTED (if cohort or case control study):

METHOD OF DATA COLLECTION
- Type: Interview / Questionnaire / Record review / Work history / Clinical tests / other:
- Details:

STUDY PERIOD:

SETTING:

STUDY POPULATION
- Total population (Total no. of persons in cohort from which the subjects were drawn):
A total of 296 patients with arteriosclerosis from Prague and central Bohemia were recruited 3 to 6 months after coronarography, acute myocardial infarction,
or ultrasound of peripheral arteries. In addition, 591 controls exhibiting no clinical signs of arteriosclerosis and lacking a personal history of CAD, PAD, or
stroke and coming from the same geographical region took part in the study.
- Selection criteria:
- Total number of subjects participating in study:
- Sex/age/race:
- Smoker/nonsmoker:
- Total number of subjects at end of study:
- Matching criteria:
- Other:

COMPARISON POPULATION
- Type: State registry / Regional registry / National registry / Control or reference group / Other comparison group:
- Details:

HEALTH EFFECTS STUDIED
- Disease(s):
- ICD No.:
- Year of ICD revision:
- Diagnostic procedure:
- Other health effects:

OTHER DESCRIPTIVE INFORMATION ABOUT STUDY:

Statistical methods:

Categorical variables were counted for each group, proportions were expressed as percents, and the difference in distribution between groups was assessed by the w2 test. The difference in distribution of continuous variables between groups was assessed by the Mann– Whitney rank sum test. Tests were considered significant at P<0.05.

Results and discussion

Any other information on results incl. tables

Acute complications

The major transient complications were dizziness (13%), sleepiness (4%), nausea (3%), and decreased or increased blood pressure (3%). In two individuals, a serious worsening of the overall clinical condition necessitated admission to hospital. It was not possible to determine whether there was a causal relationship between the MLT and the observed clinical problems.

The prevalence of complications was significantly lower in men than in women (16.5% vs 33%, χ2 =30.9, Po0.00001). For each sex, the prevalence of complications in controls was similar to that in patients (15% vs 18% χ2=0.49, P=0.48 for men, and 33% vs 30% χ2=0.20, P=0.65 for women, respectively).

Subacute adverse effects and mortality within a 30-day period after MLT

None of the subjects complained about clinical worsening of pre-existing CAD, PAD, or recurrence of stroke, or novel occurrence of CAD, PAD or stroke within 30 days after the test; in 38 subjects self-reported clinical worsening of arteriosclerosis occurred after this 30-day period. No lethal complications related to the MLT were observed in the one-month interval following methionine loading.

Applicant's summary and conclusion

Conclusions:

The methionine-loading test frequently causes transient complications, impairing perception and vigilance, but it does not have serious adverse effects on vasculature and may be considered safe.