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CDE Diabetes

Study Guide: Weight Management in Diabetes (Chapter 17)

1. Overview & Pathophysiology

Obesity is a major driver of Type 2 diabetes and complicates its management.

  • Prevalence: 80-90% of people with Type 2 diabetes have overweight or obesity. Rates are also rising in Type 1 diabetes (sevenfold increase in 20 years).
  • Benefits of Weight Loss: A modest weight loss of 5–10% of initial body weight can improve insulin sensitivity, glycemic control, and blood pressure.
  • Greater weight loss may be required to improve Obstructive Sleep Apnea (OSA) and dyslipidemia.
  • Sustained weight loss can be achieved through healthy behavior interventions, medications, or bariatric surgery.

2. Assessment of Overweight and Obesity

Assessment should go beyond just BMI to include distribution of adiposity and contributing factors.

  • Clinical Measurements:
    • Height, weight, BMI, and Waist Circumference (WC).
    • WC Risk Thresholds: cm (Men), cm (Women) indicate increased health risk.
    • Note: Ethnic-specific cut-offs exist (e.g., lower thresholds for South Asian/Chinese populations: cm for men, cm for women).
  • Contributing Factors:
    • Medications (antipsychotics, antidepressants, some antihyperglycemics).
    • Psychological factors (emotional eating, depression, ADHD).
    • Physical barriers (osteoarthritis, dyspnea).

3. Treatment Strategies

A. Healthy Behaviour Interventions

  • Cornerstone: Combined dietary modification, physical activity, and behavior therapy is most effective.
  • Structure: Interprofessional and group programs show better results than solo interventions.
  • Diet: Moderate carbohydrate reduction has shown benefits in lipids and glycemic stability.
  • Goals: Reasonable weight loss goals are 1–2 kg/month (requires ~500 kcal/day deficit).

B. Pharmacotherapy for Diabetes (Weight Considerations)

The choice of diabetes medication profoundly impacts weight.

  • Weight Gain: Insulin, Insulin Secretagogues (Sulfonylureas, Meglitinides), Thiazolidinediones (TZDs).
  • Weight Neutral: Metformin, DPP-4 Inhibitors, Acarbose.
  • Weight Loss:
    • GLP-1 Receptor Agonists: ~3 kg loss.
    • SGLT2 Inhibitors: 2–3 kg loss.

NOTE: This chapter was written in 2018 prior to the launch of semaglutide and tirzepatide.  For more up to date information please visit: Obesity Canada’s Pharmacotherapy Guideline chapter

D. Bariatric Surgery

  • Indications: Considered for Type 2 diabetes with BMI OR BMI with comorbidities (like diabetes) when other methods fail.
  • Benefits: Can lead to remission of Type 2 diabetes.
  • Procedures:
    • Roux-en-Y Gastric Bypass (RYGB): High remission rates.
    • Sleeve Gastrectomy: Effective; removes ghrelin-rich fundus.
    • Gastric Banding: Largely abandoned due to complications and lower efficacy.
  • Predictors of Remission: Higher C-peptide (good beta-cell reserve), younger age, shorter diabetes duration, no insulin use pre-op.

4. 2018 Clinical Practice Guidelines Recommendations

  1. Program: Interprofessional weight management programs are recommended for those with/at risk of diabetes to improve CV risk [Grade A, Level 1A].
  2. Medications: Weight management medications (Liraglutide 3.0 mg or Orlistat) may be considered to promote weight loss and improve glycemic control [Grade A, Level 1A].
  3. Choice of Agent: When selecting antihyperglycemic agents for adults with Type 2 diabetes and obesity, the effect on body weight should be considered [Grade D, Consensus].
  4. Surgery: Bariatric surgery may be considered for adults with Type 2 diabetes and BMI

Reference:

Wharton S, Pedersen SD, Lau DCW, Sharma AM. Weight Management in Diabetes. Canadian Journal of Diabetes. 2018;42:S124-S129. doi:10.1016/j.jcjd.2017.10.015