Effects of the transdermal nicotine patch on normalization of HDL-C and its subfractions.

BACKGROUND: Smoking reduces HDL-C and its subfractions, and smoking cessation leads to normalization of these lipoproteins. Nicotine replacement therapy is an important weapon employed by those attempting to quit smoking. This study examined the effects of the transdermal nicotine patch ("patch") on lipoproteins. METHODS: Ten male and 17 female smokers refrained from smoking for 77 days. The patch was utilized during the first 35 days and then removed for the remaining 42 days. Seven male and 9 female nonsmokers were controls. RESULTS: HDL-C, HDL(2)-C, and HDL(3)-C levels were significantly lower in smokers when compared with controls. These differences were sustained during the initial 35 days when using the patch. Over the following 42 days, however, these lipoproteins normalized to values similar to those of control subjects. Females who quit smoking gained 2.1 kg after the patch was removed. CONCLUSIONS: It was concluded that nicotine as administered by the transdermal nicotine patch inhibits normalization of HDL-C, HDL(2)-C, and HDL(3)-C in those who have quit smoking. Removal of the patch results in normalization of these lipoproteins. The patch appeared to prevent weight gain among female subjects.

Effect of ENDUROX on metabolic responses to submaximal exercise.

Claims that ENDUROX enhances performance by altering metabolic responses to exercise were tested. In a double-blind crossover design, 10 male subjects were randomly assigned to consume 400 mg of placebo or 800 mg ENDUROX for 7 days. Cycle ergometry was performed for 30 minutes at 25%, followed by 10 min at 65% of peak oxygen consumption. After a 1-week washout period, subjects performed the identical exercise protocol following 7 days of reciprocal supplemental conditions. Expired gases were collected and analyzed continuously for oxygen consumption, minute ventilation, and respiratory exchange ratio. Heart rate, blood pressure, rating of perceived exertion, blood lactate, and serum glycerol data were also collected at regular intervals. A two-way ANOVA with repeated measures revealed no significant main or interaction effects involving group differences (p > 0.05) between trials for any variable during rest, 25% or 65% (VO2 peak), or recovery. Our findings do not support the ergogenic claims for ENDUROX.

Influence of worksite environmental tobacco smoke on serum lipoprotein profiles of female nonsmokers.

The purpose of this study was to examine the influence of environmental tobacco smoke (ETS) in the workplace on high-density lipoprotein cholesterol (HDL-C), HDL-C subfractions, and apolipoprotein (apo) A-I and apo B in female workers. Premenopausal women free from factors known to influence HDL-C (cigarette smoking, vigorous physical exercise, etc) who were not taking oral contraceptives, were moderate consumers of alcohol, caffeine, and dietary fat, and were between the ages of 21 and 50 years participated in one of two groups: (1) nonsmokers who had never smoked cigarettes and were generally free from ETS exposure (nonsmokers), and (2) nonsmokers who had never smoked but were subjected to concentrated doses of ETS at least 6 hours per day, 4 days per week, for at least 6 consecutive months (ETS-exposed). A third group consisting of current cigarette smokers who smoked a minimum of 20 cigarettes per day for at least the past 5 consecutive years served as smoking control (smokers). Subjects were matched by group as closely as possible with regard to criteria that can influence blood lipoprotein levels. Participants were solicited from taverns and restaurants where they were employed. It was hypothesized that individuals chronically exposed to ETS would demonstrate unfavorable lipoprotein profiles. Results showed that HDL-C, HDL2, and apo A-I were significantly (P < .05) depressed for ETS-exposed and smokers as compared with nonsmokers. Values for ETS-exposed were not different from those for smokers. Total cholesterol, triglycerides, HDL3, and apo B did not differ among the three groups. It was concluded that excessive exposure to ETS in female workers can have deleterious effects on HDL-C, HDL2, and apo A-I in nonsmokers that are similar to effects observed in cigarette smokers. It is possible that these effects increase coronary artery disease (CAD) risk.

The influence of verbal encouragement during assessment of maximal oxygen uptake.

This study examined the influence of verbal encouragement on the attainment of maximal oxygen consumption (VO2max) for competitive runners (n = 14) and untrained non-athletes (n = 14). Two maximal treadmill tests were performed with verbal encouragement or no encouragement. VO2max, respiratory exchange ratio (RER), heart rate, and blood lactate concentration were determined. Encouragement resulted in significantly (p < 0.05) higher values for VO2max (44.9v42.8 ml/kg.min-1), treadmill run time (14.3v12.4 mins), RER (1.10 +/- 0.98), maximal heart rate (196.0v192.7 bpm) and blood lactate (110.5v93.7 mg/dl) for the untrained subjects. VO2max, RER and maximal lactate values were not affected by verbal encouragement for the competitive runners, however, treadmill run times and maximal heart rate were significantly higher with encouragement. These results suggest that attainment of VO2max is not dependent on external encouragement for highly trained competitive runners. However, encouragement may be necessary to assure attainment of VO2max for untrained non-athletes.