Global Prevalence of Obesity: Latest Estimates

The prevalence of obesity is increasing globally, with a particularly significant rise observed over the past decades in Western and Westernizing countries where rates have more than doubled in the last decade.

Regional Variations

Prevalence rates for overweight and obesity are very different in each region with the Middle East, Central and Eastern Europe and North America having higher prevalence rates. In the Middle East and North Africa, obesity prevalence is notably high, particularly among women.

In South Korea, from 2009 to 2018, the prevalence of class I, II, and III obesity increased from 29.1%, 3.2%, and 0.3% to 32.5%, 5.2%, and 0.81% respectively. The increase was particularly dramatic among young adults, with class III obesity prevalence increasing up to 3.8-fold in young men and 3.5-fold in young women.

In Germany, according to the "Study on Adult Health in Germany" (2008-2011), the prevalence of overweight (BMI ≥25 kg/m²) was 67.1% for men and 53.0% for women, while obesity (BMI ≥30 kg/m²) affected 23.3% of men and 23.9% of women. This represents an increase from 1998 when obesity rates were 18.8% for men and 21.7% for women.

A 2013 survey in Italy showed 34.85% were classified as overweight and 12.89% as obese, while in Germany the same year, 35.24% were overweight and 21.29% were obese.

In China, a 2019 study reported that the age-standardized prevalence of central obesity only, general obesity only, and both central and general obesity increased from 15.8%, 0.2%, and 2.9% in 1993 to 30.3%, 0.9%, and 10.3% in 2011, respectively. Notably, by 2011, the prevalence in rural China (30.6% for central obesity only and 10.6% for both types) exceeded that in urban areas.

Demographic Patterns

Among women in low- and middle-income countries (LMICs), 23% had obesity, with the odds of obesity being 2.72-fold higher in women than men. The sex-specific disparities varied by region, with the greatest disparities in Sub-Saharan Africa (OR 3.91).

Obesity is increasingly associated with poverty even in developing countries, and its prevalence along with related problems such as the metabolic syndrome are increasing quickly in these regions. In Saudi Arabia (2011), the prevalence of metabolic syndrome was 31.4%, with 75% of participants suffering from overweight and obesity.

Childhood Obesity

Among school children aged 6-15 years in Sakarya, Turkey (2015), the prevalence of obesity was 18.0%, with overall overweightness (including obesity) present in 26.3% of children. In Germany, 1.3 million children were overweight and 594,000 were obese in 1999, with prevalence rising from 8.9% to 15.7% for overweight and from 10.1% to 13.1% for obesity between 1994 and 1999.

With the rapid increase in the population of obese individuals, obesity has become a global problem with significant implications for public health, including increased risk of diabetes, cardiovascular disease, and other comorbidities.

Liraglutide Clinical Indications Beyond Obesity

Primary Indication

Liraglutide, a once-daily glucagon-like peptide-1 receptor agonist, is primarily approved for type 2 diabetes mellitus treatment, either as monotherapy or in combination with other medications.

Additional Clinical Indications Under Investigation

Beyond obesity and diabetes, Liraglutide has been studied for several other therapeutic applications:

• Cardiovascular outcomes - The LEADER trial demonstrated that Liraglutide reduced cardiovascular events and mortality in patients with type 2 diabetes mellitus, particularly in those with a history of myocardial infarction/stroke or established atherosclerotic cardiovascular disease.

• Cardiac function - Studies have examined Liraglutide's impact on both diastolic and systolic cardiac function, finding significant reductions in the E/A ratio and E/Ea ratio, suggesting potential clinical benefit on ventricular diastolic function.

• Vascular health - Research has shown Liraglutide reduces carotid intima-media thickness (cIMT), with this vascular benefit associated with reductions in atherogenic small dense LDL, independent of glycemic control and weight reduction.

• Lipid profile improvement - Liraglutide has demonstrated effects on plasma lipids and lipoproteins, including significant reductions in total cholesterol, triglycerides, and LDL-cholesterol.

• Blood pressure reduction - Studies have shown Liraglutide significantly decreases systolic blood pressure.

• Prediabetes - Liraglutide has been investigated for reducing the prevalence of prediabetes (84-96% reduction with 1.8-3.0 mg per day).

• Metabolic syndrome - Recent research (2023) shows liraglutide is effective in reducing metabolic syndrome components in patients with type 2 diabetes.

• Type 1 diabetes - Studied as adjunctive therapy, though it induced a smaller reduction in HbA1c and was not considered for a license in this indication.

Intervention Models in Clinical Trials

The clinical investigation of Liraglutide employs various intervention models:

• Randomized, multicentre, double-blind, double-dummy, active-controlled trials - Used to compare Liraglutide with other treatments like sitagliptin.

• Randomized controlled trials comparing Liraglutide with placebo or other drugs, alone or in combination.

• Prospective observational studies - Used to assess real-world effects, such as the study examining Liraglutide's anti-atherogenic effects.

• Add-on therapy models - Liraglutide (typically 1.2-1.8 mg/day) added to existing treatments like metformin.

• Dose titration protocols - Starting with 0.6 mg/day and titrating to 1.2 mg/day after 1 week, with some patients further increasing to 1.8 mg/day. In Japanese studies, dosing was initiated at 0.3 mg/day and increased in weekly or biweekly increments of 0.3 mg/day, to the maximum permissible dose in Japan of 0.9 mg/day.

• Long-term follow-up studies - Some trials followed patients for extended periods (up to 3.8 years in the LEADER trial) to assess sustained effects.

• Combination therapy trials - Including studies of IDegLira (insulin degludec/liraglutide combination) with a maximum dose of 50 dose steps.

Most trials administered Liraglutide via subcutaneous injection, with treatment self-administered by patients.