**Background:** Diabetes mellitus affects 9.3% of the global population (463 million in 2019), with Egypt's T2DM prevalence at 15.2%. Uncontrolled blood glucose leads to vascular and neuropathic complications affecting brain function, making T2DM patients prone to cognitive decline. Despite guidelines recommending lifestyle modification, only 17.8% of Egyptian T2DM patients achieve targeted glycemic control. This study aimed to assess the impact of a 6-month lifestyle modification program on glycemic control and cognitive function.
**Methods:** This prospective clinical trial (Feb 2016-June 2019) enrolled 184 consecutive T2DM patients (76 males, 108 females; mean age 53.8±5.4 years) via convenience sampling from outpatient clinics. Patients were allocated to an interventional group (n=92) receiving a comprehensive lifestyle modification program or a conventional group (n=92) receiving standard medical care. The intervention included seven health education sessions, two educational booklets, individualized medical nutrition therapy, physical activity recommendations (≥30 min, 3-5 days/week), biweekly phone follow-up, and WhatsApp messages over 6 months. Assessments included HbA1c, lipid profile, oxidative stress markers (MDA, GPx, GR), cognitive function (ACE III test, Trail Making Test A and B), anthropometrics, and blood pressure. Baseline characteristics were homogeneous between groups (p>0.05). The conventional group had a 35% dropout rate (60 completed follow-up).
**Key Results:** The interventional group showed significant improvements from baseline to 6 months: HbA1c decreased from 7.9±1.7% to 6.9±1.4% (p<0.001), weight decreased from 85.9±16.9 kg to 83.8±16.1 kg (p<0.001), BMI decreased from 33.3±6.2 to 32.5±5.9 (p=0.001). Lipid profile improved significantly: total cholesterol decreased from 208.4±42.6 to 182.4±39.5 mg/dL (p<0.001), LDL decreased from 134.2±35.7 to 106.1±33.4 mg/dL (p<0.001), triglycerides decreased from 130.5±67.7 to 118.4±50.2 mg/dL (p=0.041), HDL increased from 43.5±11.4 to 51.7±13.3 mg/dL (p<0.001). Oxidative stress markers improved: MDA decreased from 3.4±2.8 to 1.0±0.7 nmol/ml (p<0.001), GPx increased from 9.2±4.5 to 10.9±5.2 u/ml (p=0.020). Cognitive function improved significantly: ACE III total score increased from 89.7±5.3 to 92.04±4.4 (p<0.001), with significant improvements in fluency (8.4±2.2 to 9.3±1.9, p<0.001), language (24.9±1.5 to 25.8±0.8, p<0.001), and shape recognition (14.9±1.3 to 15.5±1.1, p=0.001). Trail Making Test A improved from 49.1±16.5 to 45.0±14.7 seconds (p=0.009) and Trail B from 106.1±42.6 to 94.0±34.5 seconds (p=0.007). The conventional group showed no significant improvements except for increased HDL (41.3±12.9 to 47.2±13.2, p=0.002) and GR (1.7±0.9 to 2.0±0.8, p=0.015). Logistic regression identified significant predictors for uncontrolled DM (HbA1c>7): conventional therapy (AOR 4.184, 95% CI 1.514-11.560, p=0.006), DM duration ≥10 years (AOR 2.939, 95% CI 1.107-7.798, p=0.030), secondary education (AOR 2.707, 95% CI 1.031-7.109, p=0.043), and baseline HbA1c>7 (AOR 2.223, 95% CI 1.613-3.065, p<0.0001). Predictors for MCI (ACE III<88) were: conventional therapy (AOR 11.512, 95% CI 3.611-36.698, p<0.0001), baseline MCI (AOR 10.849, 95% CI 3.355-35.085, p<0.0001), and female gender (AOR 4.824, 95% CI 1.344-17.317, p=0.016).
**Clinical Implications:** This study provides strong evidence that a comprehensive, multi-modal lifestyle modification program significantly improves glycemic control, lipid profiles, oxidative stress markers, and cognitive function in T2DM patients over 6 months. The findings highlight that conventional therapy alone is the strongest predictor of both poor glycemic control and cognitive impairment. The program's success using hybrid methods (face-to-face sessions, printed materials, WhatsApp messages, phone follow-up) makes it potentially scalable for resource-limited settings. However, the convenience sampling, non-randomized design, and high dropout rate (35% in conventional group) limit generalizability. Further large-scale community-based studies are warranted.