Medicines, environment and clinical pharmacology.

Medical associations and other societies have announced their theses on protection of the climate and environmental aspects in medicine. The challenges with climate change and sustainability are complex, and no quick solutions are to be found. However, basic knowledge on these issues should be available to everyone, and environmental aspects of drugs are important to all healthcare professionals. We present here a study with medical students who were introduced for the first time to environmental aspects of medicines. The results confirmed the suitability and feasibility of the approach to introduce this subject to students, and we propose that the same method can be used also when explaining the issue to medical professionals. We would like to encourage particularly clinical pharmacologists, pharmacologists and pharmacists to take a more apparent position in this field and to participate in the discussions where the strategies for the choice of medicines are considered.

Betaine supplementation decreases plasma homocysteine concentrations but does not affect body weight, body composition, or resting energy expenditure in human subjects.

BACKGROUND: Betaine (trimethylglycine) is found in several tissues in humans. It is involved in homocysteine metabolism as an alternative methyl donor and is used in the treatment of homocystinuria in humans. In pigs, betaine decreases the amount of adipose tissue. OBJECTIVE: The aim of the study was to examine the effect of betaine supplementation on body weight, body composition, plasma homocysteine concentrations, blood pressure, and serum total and lipoprotein lipids. DESIGN: Forty-two obese, white subjects (14 men, 28 women) treated with a hypoenergetic diet were randomly assigned to a betaine-supplemented group (6 g/d) or a control group given placebo for 12 wk. The intervention period was preceded by a 4-wk run-in period with a euenergetic diet. RESULTS: Body weight, resting energy expenditure, and fat mass decreased significantly in both groups with no significant difference between the groups. Plasma homocysteine concentrations decreased in the betaine group ( +/- SD: 8.76 +/- 1.63 micro mol/L at 4 wk, 7.93 +/- 1.52 micro mol/L at 16 wk; P = 0.030 for the interaction of time and treatment). Diastolic blood pressure decreased without a significant difference between the groups. Serum total and LDL-cholesterol concentrations were higher in the betaine group than in the control group (P < 0.05). CONCLUSION: A hypoenergetic diet with betaine supplementation (6 g daily for 12 wk) decreased the plasma homocysteine concentration but did not affect body composition more than a hypoenergetic diet without betaine supplementation did.

Orally administered betaine has an acute and dose-dependent effect on serum betaine and plasma homocysteine concentrations in healthy humans.

Betaine, i.e., trimethylglycine, is linked to homocysteine metabolism. A 3-mo daily betaine supplementation decreased even normal plasma total homocysteine (tHcy) concentrations in humans. The pharmacokinetic characteristics and metabolism of betaine in humans have not been investigated in detail. The aim of this study was to assess the pharmacokinetics of orally administered betaine and its acute effect on plasma tHcy concentrations. Healthy volunteers (n = 10; 3 men, 7 women) with normal body weight (mean +/- SD, 69.5 +/- 17.0 kg), 40.8 +/- 12.4 y old, participated in the study. The betaine doses were 1, 3, and 6 g. The doses were mixed with 150 mL of orange juice and ingested after a 12-h overnight fast by each volunteer according to a randomized double-blind crossover design. Blood samples were drawn for 24 h and a 24-h urine collection was performed. Orally administered betaine had an immediate and dose-dependent effect on serum betaine concentration. Single doses of 3 and 6 g lowered plasma tHcy concentrations (P = 0.019 and P < 0.001, respectively), unlike the 1-g dose. After the highest dose, the concentrations remained low during the 24 h of monitoring. The change in plasma tHcy concentration was linearly associated with betaine dose (P = 0.006) and serum betaine concentration (R2 = 0.17, P = 0.025). The absorption and elimination of betaine were dose dependent. The urinary excretion of betaine seemed to increase with an increasing betaine dose, although a very small proportion of ingested betaine was excreted via urine. In conclusion, a single dose of orally administered betaine had an acute and dose-dependent effect on serum betaine concentration and resulted in lowered plasma tHcy concentrations within 2 h in healthy subjects.