Trial Outcomes & Findings for Effects of Gastric Bypass Surgery and Calcium Metabolism and the Skeleton (NCT NCT01330914)
NCT ID: NCT01330914
Last Updated: 2019-03-15
Results Overview
Change in fractional calcium absorption, determined by dual stable isotope method. Fractional calcium absorption is the fraction of ingested calcium that is absorbed, which is expressed here as the percentage of ingested calcium that is absorbed. The 6-month change is the mean difference in percentage absorption between time points. For example, if fractional calcium absorption were to decrease from 30% preoperatively to 25% at the 6-month postoperative time point, the change in fractional calcium absorption would be -5%.
COMPLETED
55 participants
6 months (between baseline and 6 months)
2019-03-15
Participant Flow
Women and men 25-70 years of age were recruited from two academic bariatric surgery centers (the University of California, San Francisco and the San Francisco Veterans Affairs Medical Center), where surgeons used the same standardized surgical approach to Roux-en-Y gastric bypass.
Participant milestones
| Measure |
Gastric Bypass Surgery Patients
Obese men and women undergoing gastric bypass surgery
|
|---|---|
|
Overall Study
STARTED
|
55
|
|
Overall Study
COMPLETED
|
48
|
|
Overall Study
NOT COMPLETED
|
7
|
Reasons for withdrawal
| Measure |
Gastric Bypass Surgery Patients
Obese men and women undergoing gastric bypass surgery
|
|---|---|
|
Overall Study
Withdrawal by Subject
|
4
|
|
Overall Study
No longer eligible (sleeve gastrectomy)
|
3
|
Baseline Characteristics
Effects of Gastric Bypass Surgery and Calcium Metabolism and the Skeleton
Baseline characteristics by cohort
| Measure |
Gastric Bypass Surgery Patients
n=55 Participants
Obese men and women undergoing gastric bypass surgery
|
|---|---|
|
Age, Continuous
|
45.8 years
STANDARD_DEVIATION 11.2 • n=93 Participants
|
|
Sex: Female, Male
Female
|
44 Participants
n=93 Participants
|
|
Sex: Female, Male
Male
|
11 Participants
n=93 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
6 Participants
n=93 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
49 Participants
n=93 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=93 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
1 Participants
n=93 Participants
|
|
Race (NIH/OMB)
Asian
|
3 Participants
n=93 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
2 Participants
n=93 Participants
|
|
Race (NIH/OMB)
Black or African American
|
12 Participants
n=93 Participants
|
|
Race (NIH/OMB)
White
|
37 Participants
n=93 Participants
|
|
Race (NIH/OMB)
More than one race
|
0 Participants
n=93 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=93 Participants
|
|
Region of Enrollment
United States
|
55 participants
n=93 Participants
|
|
Menopausal status
Premenopausal
|
30 participants
n=93 Participants
|
|
Menopausal status
Postmenopausal
|
14 participants
n=93 Participants
|
|
Menopausal status
N/A (Men)
|
11 participants
n=93 Participants
|
|
Weight
|
122.7 kg
STANDARD_DEVIATION 19.3 • n=93 Participants
|
|
Body mass index
|
44.2 kg/m2
STANDARD_DEVIATION 7.0 • n=93 Participants
|
|
Percentage body fat
|
46.7 percentage of body fat
STANDARD_DEVIATION 5.9 • n=93 Participants
|
|
Diabetes status
Diabetic
|
22 participants
n=93 Participants
|
|
Diabetes status
Not diabetic
|
33 participants
n=93 Participants
|
|
Femoral neck areal bone mineral density (DXA)
|
0.949 g/cm2
STANDARD_DEVIATION 0.133 • n=93 Participants
|
|
Spine volumetric bone mineral density (QCT)
|
0.159 g/cm3
STANDARD_DEVIATION 0.036 • n=93 Participants
|
PRIMARY outcome
Timeframe: 6 months (between baseline and 6 months)Population: Participants from the cohort who underwent assessment of fractional calcium absorption preoperatively and 6 months postoperatively
Change in fractional calcium absorption, determined by dual stable isotope method. Fractional calcium absorption is the fraction of ingested calcium that is absorbed, which is expressed here as the percentage of ingested calcium that is absorbed. The 6-month change is the mean difference in percentage absorption between time points. For example, if fractional calcium absorption were to decrease from 30% preoperatively to 25% at the 6-month postoperative time point, the change in fractional calcium absorption would be -5%.
Outcome measures
| Measure |
Gastric Bypass Surgery Patients
n=33 Participants
Obese men and women undergoing gastric bypass surgery
|
|---|---|
|
Change in Intestinal Calcium Absorption
|
-25.8 % of ingested calcium that is absorbed
Standard Deviation 15.3
|
SECONDARY outcome
Timeframe: 12 months post-operatively (between baseline and 12 months)Population: participants who underwent DXA at pre-op and 12-month post-op time points
Areal BMD at the femoral neck by dual-energy X-ray absorptiometry (DXA). The 12-month change is the percentage change between the 12 month and baseline time points.
Outcome measures
| Measure |
Gastric Bypass Surgery Patients
n=45 Participants
Obese men and women undergoing gastric bypass surgery
|
|---|---|
|
Areal Bone Mineral Density (BMD) at the Femoral Neck
|
-8.0 percent of baseline value
Standard Deviation 4.9
|
SECONDARY outcome
Timeframe: 12 months post-operatively (between baseline and 12 months)Population: participants who underwent HR-pQCT at pre-op and 12-month post-op time points
Trabecular number at the tibia by high-resolution peripheral quantitative computed tomography (HR-pQCT). The 12-month change is the percentage change between the 12 month and baseline time points. HR-pQCT images were analyzed using the manufacturer's standard clinical evaluation protocol, with trabecular structure extracted using a threshold-based binarization process.
Outcome measures
| Measure |
Gastric Bypass Surgery Patients
n=44 Participants
Obese men and women undergoing gastric bypass surgery
|
|---|---|
|
Trabecular Number at the Tibia
|
-4.6 percent of baseline value
Standard Deviation 8.4
|
Adverse Events
Gastric Bypass Surgery Patients
Serious adverse events
| Measure |
Gastric Bypass Surgery Patients
n=55 participants at risk
Obese men and women undergoing gastric bypass surgery
|
|---|---|
|
Renal and urinary disorders
Nephrolithiasis
|
1.8%
1/55 • Number of events 1 • 12 months
Participants were asked about interim adverse events at baseline, 6-month, and 12-month study visits. Adverse events volunteered by participants between study visits were also recorded.
|
Other adverse events
| Measure |
Gastric Bypass Surgery Patients
n=55 participants at risk
Obese men and women undergoing gastric bypass surgery
|
|---|---|
|
Gastrointestinal disorders
Constipation
|
1.8%
1/55 • Number of events 1 • 12 months
Participants were asked about interim adverse events at baseline, 6-month, and 12-month study visits. Adverse events volunteered by participants between study visits were also recorded.
|
|
Gastrointestinal disorders
Dyspepsia
|
3.6%
2/55 • Number of events 2 • 12 months
Participants were asked about interim adverse events at baseline, 6-month, and 12-month study visits. Adverse events volunteered by participants between study visits were also recorded.
|
|
Renal and urinary disorders
Nephrolithiasis
|
1.8%
1/55 • Number of events 1 • 12 months
Participants were asked about interim adverse events at baseline, 6-month, and 12-month study visits. Adverse events volunteered by participants between study visits were also recorded.
|
Additional Information
Dr. Anne Schafer
San Francisco Veterans Affairs Medical Center
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place