Improving Glycemic Control and Variability in Prediabetes: Insights from a 1-Week Intensive Exercise and Diet Intervention Using CGM – A Single-Case Study  / Prediyabette Glisemik Kontrol ve Değişkenliğin İyileştirilmesi: CGM Kullanılarak 1 Hafta Süren Yoğun Egzersiz ve Diyet Müdahalesinden Elde Edilen Bulgular – Tek Vaka Çalışması: Improving Glycemic Control and Variability in Prediabetes

Begüm YÜCESOY GÜNEYSU; Özgür KASIMAY; Hasan Birol ÇOTUK

Authors

Begüm YÜCESOY GÜNEYSU Marmara University
Özgür KASIMAY
Hasan Birol ÇOTUK

Keywords:

Prediabetes, Continuous glucose monitoring, Glycemic variability, Aerobic Exercise

Abstract

ABSTRACT

Aim: This single-case study aimed to investigate the acute effects of a structured diet and exercise protocol on glycemic control and variability in a sedentary prediabetic individual, using continuous glucose monitoring.

Material and Method: A 40-year-old female with prediabetes underwent a 6-day controlled intervention with a fixed macronutrient diet and three daily sessions of moderate-intensity continuous cycling on an ergometer. Interstitial glucose was monitored via Medtronic iPro2 CGM at 5-min intervals. Glycemic metrics (mean glucose, time in range, variability) were analyzed for 24-h, daytime, and nighttime using Glyculator 3.0 software per international consensus. Pre- and post-intervention assessments included body composition and fasting metabolic parameters (insulin, HOMA-IR).

Results: Fasting insulin decreased from 16 to 8.91 µIU/mL; HOMA-IR from 3.55 to 1.98. CGM showed mean glucose of 106.88 mg/dL, 100% time in range (70-180 mg/dL), but elevated glycemic variability (higher daytime vs. nighttime). Pre-meal exercise consistently blunted postprandial glucose peaks. Body composition improved.

Conclusion: Short-term lifestyle intervention rapidly enhanced insulin sensitivity and body composition. CGM detected high variability despite normal averages, underscoring its role in early dysglycemia detection and personalized guidance on exercise timing.

Keywords: Aerobic Exercise, Continuous Glucose Monitoring, Glycemic Variability, Prediabetes.

ÖZET

Amaç: Bu tek vaka gözlem çalışması, prediyabetli sedanter bir bireyde, 1 haftalık yapılandırılmış diyet ve egzersiz protokolünün glisemik kontrol ve değişkenlik üzerindeki akut etkilerini sürekli glikoz izleme (SGİ) ile araştırmayı amaçlamıştır.

Materyal ve Metod: Prediyabetli 40 yaşında kadın katılımcı, sabit makro besin diyeti ve bisiklet ergometresinde günde üç seans orta yoğunluklu sürekli antrenman (OYSA) içeren 6 günlük kontrollü müdahaleye alındı. Glukoz, Medtronic iPro2 SGİ cihazıyla izlendi. Glisemik ölçümler uluslararası konsensüse göre hesaplandı; veriler Glyculator 3.0 ile 24 saat, gündüz ve gece için analiz edildi. Vücut kompozisyonu ve metabolik parametreler müdahale öncesi ve sonrası değerlendirildi.

Bulgular: Açlık insülini (16'dan 8,91 µIU/mL) ve HOMA-IR (3,55'ten 1,98) düştü. CGM'de ortalama glukoz 106,88 mg/dL ve hedef aralıkta kalma süresi (TIR) (70-180 mg/dL) %100 olmasına rağmen, glisemik değişkenlik yüksekti (değişim katsayısı CV: %14,67; glisemik eksürsyonların ortalama genliği MAGE: 28,07 mg/dL). Gündüz değişkenliği geceye göre daha yüksekti. Yemek öncesi egzersiz, yemek sonrası glukoz artışlarını belirgin şekilde azalttı.

Sonuç: Kısa süreli yapılandırılmış yaşam tarzı müdahalesi, prediyabette insülin duyarlılığını ve vücut kompozisyonunu hızla iyileştirdi. SGİ, normal ortalama glukoza rağmen artmış glisemik değişkenliği ortaya koyarak, erken disgliseminin saptanması ve egzersiz zamanlaması gibi kişiselleştirilmiş tedavi kılavuzluğunda değerli bir araç olabileceğini gösterdi.

Anahtar Kelimeler: Aerobik Egzersiz, Glisemik Değişkenlik, Prediyabet, Sürekli Glukoz Izleme.

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