Preoperatively and at 3, 6, and 12 months postoperatively, height (m) and weight (kg) were recorded and pulmonary function tests were obtained in all patients. We accepted data within 60 days of the anniversary date. If more than one study was performed within a given time period, the study most remote from the surgery was accepted. The height and weight were used to calculate the body mass index (BMI) using the following formula: BMI = weight (kg)/[height (m)]2.
Statistical analysis was performed using Statview 4.5 (SAS Institute; Cary, NC). The data are expressed as mean ± SEM. Data were analyzed using t tests. Simple linear regression was used to compare changes in weight and changes in pulmonary function. A p value of < 0.05 was accepted as significant. mycanadianpharmacy.com
Forty-six patients underwent bilateral LVRS between January 1995 and April 1996. Demographics of these patients are shown in Table 1. There were three deaths, for a 6.5% mortality rate. All three deaths occurred in the immediate postoperative period. At the end of the study period, 43 patients were eligible for a 12-month follow-up visit, and 38 of those patients returned for repeat pulmonary function testing within 60 days of their surgical anniversary. There were roughly equal numbers of male and female patients. The mean BMI at baseline was not statistically different (unpaired t test, p = 0.65) in men and women.
Change in Weight After LVRS
The change in body weight for the 38 patients over time is shown in Figure 1. There was an initial slight weight loss 3 months after surgery. By 6 months, the average weight gain was just under 2 kg; at 12 months, the average weight gain was 3.8 ± 0.9 kg, This represents a 6.3% gain in weight compared with the preoperative weight for the 38 patients who returned for a 12-month follow-up. The number of patients returning for 12-month follow-up represents 88% (38 of 43) of the eligible patients. Of the five patients who did not have a pulmonary function test during the window defined for 12-month follow-up, three patients demonstrated weight gain (1.59, 0.44, and 3.17 kg) and two patients had weight loss (—3.63 and —0.68 kg) in visits either before or after the allowed time period. The range of weight change at 12 months was large (—10.4 to 16.3 kg); however, all but seven patients gained weight at 12 months. We also examined a group of patients who were evaluated for LVRS but did not have the surgery, and returned for a follow-up visit after 1 year. Twenty-nine patients met those criteria. In contrast to patients who underwent LVRS, this group gained significantly less weight (Fig 2; p < 0.02; unpaired t test).
Table 1—Characteristics of 46 Patients
|mean ± SEM||06|
|BMI (mean ± SEM)|
|Men||24.0 ± 1.1|
|Women||23.4 ± 0.8|
Figure 1. Effect of LVRS on body weight over time. Data expressed as changes in body weight in kg (mean ± SEM) over time after LVRS.
Figure 2. Effect of LVRS vs no surgery on body weight in patients who underwent LVRS and in a group of patients evaluated for LVRS who did not undergo surgery. Data expressed as body weight change (% ± SEM) at 1 year compared with baseline body weight. Weight gain was significantly greater (p < 0.03, unpaired t test) in the LVRS group.