title: Height, predictors of C-peptide and cancer risk in men. Fructose and insulin sensitivity in patients with type 2 diabetes.
abstract: BACKGROUND Excessive energy intake tends to increase circulating levels of insulin and free insulin-like growth factor-1 ( IGF-I ) , which may increase risk of some cancers that are common in Western countries . However , the relative importance of these hormonal factors during pre-adulthood and adulthood is unknown . METHODS We prospect ively examined height , as a marker of pre-adult IGF-I bioactivity , and modifiable adult determinants of insulin secretion , in relation to risk of cancer , particularly Western-related cancers ( colon , pancreas , kidney , and aggressive prostate cancers ) in 47,690 male health professionals . Information about dietary and lifestyle factors for these men was collected at baseline ( 1986 ) and was up date d periodically . A  C-peptide score  , representing insulin secretion , was created by using body mass , physical activity , and diet in a stepwise linear regression to predict C-peptide level , in a sample of 263 cohort members . RESULTS From 1986 to 1998 , we documented 3270 incident cancers ( excluding the less aggressive prostate cancers ) . Greater body mass index , lower physical activity , and a Western dietary pattern were independent predictors of higher plasma C-peptide levels in the sample . A C-peptide score , based on these variables , was positively related to risk of Western-related cancers , but not to other cancer types in the entire cohort . Height was also only related to Western-related cancers . For Western-related cancers , 29 % ( 95 % CI : 16 % , 48 % ) were attributed to C-peptide scores above the first decile , 30 % ( 95 % CI : 11 % , 58 % ) to heights > or=66 inches , and 49 % ( 95 % CI : 30 % , 69 % ) to both factors combined . For total cancers , 29 % ( 95 % CI : 16 % , 46 % ) were attributable to both factors . CONCLUSIONS Maximal growth in the pre-adult period and hyperinsulinaemia during adulthood may largely underlie the excess risk of some cancers that are common in Western population s. A substantial proportion of these cancers may be modifiable in adulthood , through alterations in body weight , sedentary behaviour , and dietary patterns that stimulate hyperinsulinaemia The effect of dietary fructose ( 20 % of carbohydrate calories , 45 - 65 g day-1 for 4 weeks ) on glycaemic control , serum lipid , lipoprotein and apoprotein A-I and A-II concentrations and on insulin sensitivity was studied in 10 type 2 diabetic patients . The study was done in a r and omized , double-blind fashion with crystalline fructose or placebo administered evenly during 4 meals or snacks per day . The patients were hospitalized throughout the study periods . The fasting plasma glucose concentration decreased during the fructose ( from 10.7 + /- 1.4 mmol l-1 to 8.0 + /- 0.8 mmol l-1 , P < 0.02 ) and the control diet ( from 10.1 + /- 0.9 mmol l-1 to 8.0 + /- 0.7 mmol l-1 , P < 0.05 ) . The mean diurnal blood glucose concentration also fell both during the fructose ( from 10.8 + /- 0.5 mmol l-1 to 8.4 + /- 0.3 mmol l-1 , P < 0.001 ) and the control diet ( from 10.3 + /- 0.3 mmol l-1 to 8.8 + /- 0.9 mmol l-1 , P < 0.01 ) . The HbA1 concentration improved ( P < 0.02 ) only during the fructose diet . Insulin sensitivity increased by 34 % ( P < 0.05 ) during the fructose diet , but remained unchanged during the control period . Serum insulin , triglyceride , apoprotein A-I and A-II concentrations , body weight , blood pressure and blood lactate remained unchanged during both diets . In conclusion , substitution of moderate amounts of fructose for complex carbohydrates can improve glycaemic control and insulin sensitivity in patients with type 2 diabetes
target: Fructose consumption did not significantly affect fasting glucose or insulin .
  A priori subgroup analyses showed no evidence of effect modification on any end point .
  Isocaloric exchange of fructose for other carbohydrate improves long-term glycemic control , as assessed by glycated blood proteins , without affecting insulin in people with diabetes .
background: OBJECTIVE The effect of fructose on cardiometabolic risk in humans is controversial .
  We conducted a systematic review and meta- analysis of controlled feeding trials to clarify the effect of fructose on glycemic control in individuals with diabetes .