Dietary carbohydrate dictates development of Type 2 diabetes in the Nile rat.
Amount and type of dietary carbohydrate (CHO), as well as the CHO:fat ratio, are thought to be critical for both the rate of development and severity of Type 2 diabetes mellitus. Thus, these nutritional considerations were examined in the previously described "spontaneous" model of diabetes and metabolic syndrome, the Nile rat. Weanling male Nile rats (n=92) were fed semipurified diets, modifying glycemic index and load by changing the amount of fiber or altering the CHO:fat ratio. Random and fasting blood glucose and body weight were assessed, and diabetes was characterized in terms of blood glucose, relevant plasma and liver parameters, food and water intake and terminal organ weights. Nile rats fed with hiCHO became more hyperglycemic than rats fed with modCHO (P<.05), while loCHO and hiCHO+hiFiber rats remained essentially normoglycemic. Liver lipid and glycogen accumulation was associated with severe hyperlipemia in diabetic rats, analogous to metabolic syndrome in humans. Advanced diabetes was linked to liver and kidney damage and elevated blood urea nitrogen with weight loss. Dispersing dietary CHO by fiber or replacing it by moderate fat (reducing the glycemic index and load) delayed the onset of diabetes but did not prevent signs of insulin resistance. A very low content of dietary CHO (high fat) seemed to prevent even these early indicators of insulin resistance. Thus, the Nile rat represents a novel CHO-sensitive model for study of Type 2 diabetes that reliably follows the course of disease in humans.
Foster Biomedical Research Laboratory, Brandeis University, Waltham, MA 02454, USA. Electronic address: juliab@brandeis.edu.
Julia
J
Bolsinger
Andrzej
A
Pronczuk
K C
KC
Hayes
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D004040:Dietary Carbohydrates / Q000008:administration & dosage* / Q000378:metabolism; D004041:Dietary Fats / Q000008:administration & dosage; D004043:Dietary Fiber / Q000008:administration & dosage; D006949:Hyperlipidemias / Q000209:etiology; D007333:Insulin Resistance; D008297:Male; D051381:Rats
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004043:Dietary Fiber
BUN; CHO; Carbohydrate; DIO; FBG; Glycemic index; Glycemic load; HDL-C; Insulin resistance; LDL-C; MetS; NR; Nile rat; PLSD; RBG; T2DM; TC; TG; Type 2 diabetes; blood urea nitrogen; carbohydrate; diet-induced obesity; fasting blood glucose; high-density lipoprotein-cholesterol; low-density lipoprotein-cholesterol; metabolic syndrome; protected least significant difference; random blood glucose; total cholesterol; triglycerides; type 2 diabetes mellitus