Statistical analysis
Continuous variables were summarized using descriptive statistics
presented as mean and standard deviation (SD). Categorical variables
were summarized using counts and percentages. Categorical data were
analyzed using the Chi-square (χ2) test or Fisher exact test
appropriately. Student’s t-test and analysis of variance were used for
parametric variables.
A multiple regression analysis was performed to define the relationship
between vertebral fractures and the following variables: age, gender,
duration of chronic renal failure (CRF), duration of hemodialysis, time
from renal transplantation, BMI, creatinine, PTH, creatinine, lumbar
spine BMD, lumbar spine Z score, femoral neck BMD, and femoral neck Z
score.
Two different multiple regression analyses were also performed to
determine the relationship between lumbar BMD and femoral neck BMD and
parameters. Age, gender, duration of CRF, duration of hemodialysis, time
from renal transplantation, BMI, creatinine, PTH, creatinine, and 25-OH
vitamin D were used as independent variables.
Multiple regression analysis parameters with a possible influence on PTH
were added as covariates; age, gender, duration of CRF, BMI, calcium,
phosphorous, and 25-OH vitamin D.
The results were evaluated at a 95% confidence interval, and p
<0.05 was considered statistically significant. All
statistical analyses were performed using software (GraphPad InStat 3.0;
GraphPad Software, Inc., San Diego, CA, USA).