Higher Fat Intake Linked to Increased Insulin Resistance, Adverse Vascular Profile in T1D

Higher intake of fat, but not carbohydrates, is associated with increased insulin resistance (IR) and adverse vascular profile in patients with type 1 diabetes (T1D), according to a study published in the European Journal of Nutrition.

According to the study authors, this is the first report demonstrating dietary intake is linked to IR and an adverse vascular profile in patients with T1D.

To come to this finding, the authors pooled baseline data from 3 randomized controlled trials (RCTs), using estimated glucose disposal rate (eGDR) as a marker for IR. Multivariate nutrient density substitution models were used to examined the association between macronutrient composition and IR and vascular biomarkers, including tumor necrosis factor-α (TNF- α), fibrinogen, tissue factor (TF) activity, and plasminogen activator inhibitorn-1 (PAI-1).

A total of 107 patients were included in the current analysis. About half were male, and the mean (SD) age was 29 (6) years. The authors noted that participants with lower eGDR were older with a longer T1D duration, higher insulin requirements, and an adverse vascular profile (P < .05).

Participants self-reported their intake using 2 methods, a 48-hour weighed food diary and the Dietary Instrument for Nutrition Education (DINE) Food Frequency Questionnaire (FFQ). From this information, fat intake was categorized into 3 groups with frequency of fat consumption converted into a score:

• DINE1 or low intake; score < 30; equivalent to ≤ 83 g/day
• DINE2 or moderate intake; score between 30 and 40; equivalent to 84-122 g/day
• DINE3 or high intake; score > 40; equivalent to > 122 g/day

Patients were also stratified by eGDR tertiles, with lower eGDR values, measured in mg/kg/min, conferring higher degrees of IR; eGDR tertiles were < 5.1, 5.1-8.6, and ≥ 8.7 mg/kg/min/.

The authors found that daily energy intake was inversely correlated with eGDR.

Compared with patients with lower degrees of IR, patients with increased IR had statistically significant (P < .001) higher total energy intake (kcal/d).

• For eGDR < 5.1, mean energy intake was 3192 (566)
• For eGDR 5.1-8.6, mean energy intake was 2772 (268)
• For eGDR ≥ 8.7, 2626 (395)

Patients with increased IR also consumed a higher absolute and proportional amount of fat, with means (SD) of 47.6% (18.6%), 30.4% (8.1%), and 25.8% (10.4%), respectively (P < .001).

After adjusting for total energy intake, age, sex, and T1D duration, the authors found that increased carbohydrate intake offset by an isoenergetic decrease in fat was associated with higher eGDR (β = 0.103; 95% CI, 0.044-0.163).

However, increased dietary fat at the expense of dietary protein intake was associated with lower eGDR (β = −0.119; 95% CI, −0.199 to −0.040).

Additionally, replacing fat with 5% isoenergetic amount of carbohydrate resulted in decreased vascular biomarkers (P < .05).

“Future research is required to explore the impact of diet in greater detail with a specific focus on individual dietary components, including diet quality, processing, and timing, thus enabling more accurate and personalized individually dietary management,” the authors concluded. “A different dietary assessment tool such as 7-day food diary may also be required to better display dietary patterns in this group.”

Reference

Kietsiriroje N, Shah H, Zare M, et al. Dietary fat intake is associated with insulin resistance and an adverse vascular profile in patients with T1D: a pooled analysis. Eur J Nutr. Published online December 10, 2022. doi:10.1007/s00394-022-03070-z