Association between glycemic index, glycemic load, and fructose with insulin resistance: the CDC of the Canary Islands study.
BACKGROUND
The involvement of carbohydrates in triggering insulin resistance (IR) remains a source of controversy.


OBJECTIVE
To study the relation between glycemic index (GI), glycemic load (GL), and fructose with insulin resistance in a predominantly rural population in the Canary Islands.


METHODS
Cross-sectional study carried out in 668 nondiabetic people aged 18-75. IR was estimated with serum glucose and C-peptide (HOMA2-IR). Nutrient intakes were obtained from a validated food frequency questionnaire. ANOVA was used to analyze nutrient distribution across quartiles of HOMA2-IR. Four multivariate nutrient density models (dependent variable: log-transformed HOMA2-IR) which differed only in the kinds of carbohydrates included were tested (Model 1: carbohydrates; Model 2: GI and then GL; Model 3: free fructose, other simple sugars and starch; Model 4: total fructose, remaining sugars and starch).


RESULTS
There was no association between GI and IR. There was a direct association between GL (P < 0.001), fructose (free [P = 0.001], total [P = 0.013]), energy intake (P < 0.001), fruit fiber (<0.001), and glucose (P = 0.003) with IR. There was an inverse association between cereal (P = 0.008) and vegetable fiber (P < 0.001) and IR. Multivariate models corroborated the association of carbohydrates, GL, fructose, vegetable fiber, and energy intake with IR. The association between GL and IR disappeared when Model 2 was adjusted by total fructose intake.


CONCLUSIONS
There was a direct association between fructose intake and IR. There was no relationship between GI and IR. Although a direct association of GL with IR was detected, it was attributable to the consumption of fructose.
Domínguez Coello
Santiago
S
Primary Health Care Research Unit, La Candelaria University Hospital, Santa Cruz de Tenerife, Canary Islands, Spain. sdominguezc@telefonica.net
Cabrera de León
Antonio
A
Rodríguez Pérez
María C
MC
Borges Álamo
Carlos
C
Carrillo Fernández
Lourdes
L
Almeida González
Delia
D
García Yanes
Jezabel
J
González Hernández
Ana
A
Brito Díaz
Buenaventura
B
Aguirre-Jaime
Armando
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000209:etiology; D004032:Diet / Q000706:statistics & numerical data*; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000145:classification / Q000378:metabolism; D004043:Dietary Fiber / Q000008:administration & dosage / Q000378:metabolism; D004044:Dietary Proteins / Q000008:administration & dosage / Q000378:metabolism; D002149:Energy Intake; D005260:Female; D005632:Fructose / Q000008:administration & dosage* / Q000378:metabolism*; D038321:Glycemic Index; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D013030:Spain; D011795:Surveys and Questionnaires; D055105:Waist Circumference; D055815:Young Adult
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004043:Dietary Fiber; D004044:Dietary Proteins; D007328:Insulin; D005632:Fructose