the sample included 847 white and 553 african american diabetic adults ( 1869 years of age ) from the pennington center longitudinal study ( pcls ) , which is an investigation of the effects of obesity and lifestyle factors on the development of chronic diseases and premature mortality . the sample is composed of volunteers who participated in studies conducted at the pennington biomedical research center ( pbrc ) in baton rouge , louisiana , between 1994 and 2009 ( 14,15 ) . each participant was seen once at baseline , and mortality outcomes were assessed by linkage with the national death index . written informed consent was provided , and all procedures were approved by the pbrc institutional review board . diabetes status was determined using a combination of self - reported physician diagnosis , fasting blood glucose ( 126 mg / dl ) , and diabetic medications . height and weight were measured after outer clothing , heavy pocket items , and shoes were removed , and bmi was calculated ( weight [ kg]/height [ m ] ) . wc was measured at the midpoint between the inferior border of the ribcage and the superior aspect of the iliac crest . age was computed from birth and observation dates , and year of examination was included as a covariate to account for potential temporal trends in baseline measurements . smoking status , alcohol consumption , and leisure - time physical activity were self - reported by questionnaire . the vital status of all participants was determined by linkage to the national death index ( 16 ) . the primary end point for this analysis was deaths from all causes that occurred between 6 months after the baseline assessment and 31 december 2009 . the average length of follow - up was 6.7 years ( sd 3.6 ; maximum 15.8 ) . cox proportional hazards regression was used to assess the associations of wc and bmi with all - cause mortality , adjusting for age , sex , race , baseline examination year , smoking status , alcohol consumption , and physical activity . model 1 included age , sex and baseline examination year as covariates , and model 2 additionally included race ( white , african american ) smoking status ( never , former , current , unknown ) , alcohol consumption ( no , yes , unknown ) , and leisure - time physical activity ( < 4 h / week , 4 h / week , unknown ) . hazard ratios ( hrs ) are expressed per sd of each independent variable ( wc = 15 cm ; bmi = 7 kg / m ) . the presence of interactions was tested by including race , sex , wc , and bmi interaction terms in the models . to compare dose - response associations , the sample included 847 white and 553 african american diabetic adults ( 1869 years of age ) from the pennington center longitudinal study ( pcls ) , which is an investigation of the effects of obesity and lifestyle factors on the development of chronic diseases and premature mortality . the sample is composed of volunteers who participated in studies conducted at the pennington biomedical research center ( pbrc ) in baton rouge , louisiana , between 1994 and 2009 ( 14,15 ) . each participant was seen once at baseline , and mortality outcomes were assessed by linkage with the national death index . written informed consent was provided , and all procedures were approved by the pbrc institutional review board . diabetes status was determined using a combination of self - reported physician diagnosis , fasting blood glucose ( 126 mg / dl ) , and diabetic medications . height and weight were measured after outer clothing , heavy pocket items , and shoes were removed , and bmi was calculated ( weight [ kg]/height [ m ] ) . wc was measured at the midpoint between the inferior border of the ribcage and the superior aspect of the iliac crest . age was computed from birth and observation dates , and year of examination was included as a covariate to account for potential temporal trends in baseline measurements . smoking status , alcohol consumption , and leisure - time physical activity were self - reported by questionnaire . the vital status of all participants was determined by linkage to the national death index ( 16 ) . the primary end point for this analysis was deaths from all causes that occurred between 6 months after the baseline assessment and 31 december 2009 . the average length of follow - up was 6.7 years ( sd 3.6 ; maximum 15.8 ) . cox proportional hazards regression was used to assess the associations of wc and bmi with all - cause mortality , adjusting for age , sex , race , baseline examination year , smoking status , alcohol consumption , and physical activity . model 1 included age , sex and baseline examination year as covariates , and model 2 additionally included race ( white , african american ) smoking status ( never , former , current , unknown ) , alcohol consumption ( no , yes , unknown ) , and leisure - time physical activity ( < 4 h / week , 4 h / week , unknown ) . hazard ratios ( hrs ) are expressed per sd of each independent variable ( wc = 15 cm ; bmi = 7 kg / m ) . the presence of interactions was tested by including race , sex , wc , and bmi interaction terms in the models . to compare dose - response associations , a total of 86 deaths ( 33 from cardiovascular disease , 23 from cancer , and 30 from other causes ) occurred during 9,316 person - years of follow - up . at baseline , decedents were significantly older ( 57.0 [ sd 7.5 ] vs. 53.3 [ 9.5 ] years ) , had a higher mean wc ( 115.4 [ 16.0 ] vs. 110.2 [ 15.1 ] cm ) than survivors , and a lower percentage were women ( 48.8 vs. 66.7% ; supplementary table ) . mean bmi did not differ between decedents and survivors ( 36.3 [ 7.1 ] vs. 35.4 [ 6.6 ] kg / m ) nor did the percentage of african americans ( 39.5 vs. 39.5% ) . in models adjusted for age , sex , and examination year , wc ( hr 1.41 [ 95% ci 1.151.73 ] ) and bmi ( 1.32 [ 1.071.64 ] ) were significantly associated with mortality . in multivariable - adjusted models , wc ( 1.40 [ 1.141.72 ] ) and higher death rates were observed in men ( 1.78 [ 1.122.81 ] ) and african americans ( 1.69 [ 1.082.66 ] ) after adjustment for wc . there were significant linear trends for mortality across tertiles of both wc and bmi . in both cases , participants in tertile 3 had a significantly elevated risk of mortality compared with tertile 1 . hrs for all - cause mortality across tertiles of bmi ( a ) and wc ( b ) are shown among patients with diabetes in the pennington center longitudinal study . cutoffs for the tertiles were 32 and 38 kg / m for bmi and 104 and 116 cm for wc . hrs are adjusted for age , year of examination , sex , race , smoking , alcohol consumption , and physical activity . the results of this study indicate a significant , positive association between bmi and mortality rates in this biracial sample of patients with diabetes . this is in contrast to some previous studies that have documented inverse ( 69 ) or u - shaped associations ( 10,11 ) . however , our results are similar to those from finnish patients with diabetes , where the hrs across successive tertiles of bmi were 1.00 ( reference ) , 0.94 ( 95% ci 0.801.10 ) , and 1.20 ( 1.021.40 ) ( 5 ) . the reasons for different associations across studies are not clear ; however , the samples differed at baseline by mean level of bmi , health status , ethnicity , and duration of diabetes . to our knowledge , the role of obesity in predicting mortality among patients with diabetes has not been explored using measures other than bmi . our results indicate that decedents had a higher wc but not a higher bmi than survivors at baseline . the reliance on direct assessments of wc and bmi and the linkage to the national death index are marked strengths . however , the relatively small , nonrepresentative sample and the lack of information on duration of diabetes and comorbidities are limitations . the sample size was not sufficient to allow for cause - specific analyses . in conclusion , the results of this study indicate that maintaining a healthy wc and bmi are important for individuals living with diabetes .
objectivewe aimed to determine the associations of waist circumference ( wc ) and bmi with all - cause mortality among patients with diabetes.research design and methodsthe sample included 847 white and 553 african american patients ( 1869 years of age ) with diabetes . 
 height , weight , and wc were measured , and the bmi ( kg / m2 ) was calculated . 
 cox regression was used to analyze the associations of bmi and wc with mortality , adjusting for age , sex , race , examination year , smoking status , alcohol consumption , and physical activity . 
 hazard ratios ( hrs ) are expressed per standard deviation of each independent variable.resultsa total of 86 deaths occurred during 6.7 years of follow - up . 
 after adjustment for covariates , wc ( hr 1.40 [ 95% ci 1.141.72 ] ) and bmi ( 1.29 [ 1.041.61 ] ) demonstrated significant relationships with mortality.conclusionsthe results indicate that maintaining a healthy wc and bmi are both important for individuals living with diabetes .