Type 2 diabetes (T2D) is a chronic metabolic disease resulting from a combination of insulin resistance and impaired insulin secretion by the pancreatic β-cells of the islets of Langerhans. This condition is often associated with behavioral and environmental factors such as obesity, a sedentary lifestyle, a high-calorie diet, and genetic predisposition [1] - [3] . T2D accounts for nearly 90% of diabetes cases worldwide, affecting millions of individuals and leading to severe chronic complications, including cardiovascular, renal, and neurological diseases [3] [4] .

According to the International Diabetes Federation (IDF), 537 million adults had diabetes in 2021, and this number is projected to reach 783 million by 2045 [5] . Although Africa has a lower prevalence compared to other regions (approximately 4.5%), the continent is experiencing the fastest growth in diabetes cases, with a projected 129% increase by 2045 [6] . In Cameroon, the diabetes prevalence was estimated at 5.8% in 2019, predominantly in urban areas due to nutritional transition and modern lifestyles [7] .

Body composition, including body mass index (BMI), muscle mass, bone mass, body water percentage, total body fat, and visceral fat, plays a central role in the development and progression of T2D. Excess visceral fat, in particular, releases inflammatory cytokines and free fatty acids that disrupt insulin signaling, thereby promoting insulin resistance [8] [9] . Simultaneously, reduced muscle mass lowers glucose uptake capacity, exacerbating hyperglycemia [10] [11] . These changes are accompanied by molecular alterations, including chronic activation of pro-inflammatory pathways (NF-κB, JNK) and decreased expression of GLUT-4 transporters in skeletal muscles [12] .

Studying variations in body composition parameters based on T2D risk levels is essential for identifying predictive biomarkers and developing targeted preventive strategies. Given the growing prevalence of T2D, particularly in resource-limited settings like Cameroon, understanding how different body composition components influence disease risk is critical.

The primary objective of this study was to evaluate variations in body composition parameters (BMI, muscle mass, bone mass, body water percentage, body fat percentage, and visceral fat) based on T2D risk levels. This analysis aimed to identify significant differences among groups at low risk, increased risk, and individuals at 10-year risk, to better understand the role of body composition in the occurrence of T2D.

Data were analyzed using R software version 4.4.2 and GraphPad version 8.4.3 for Windows. Qualitative variables were presented as frequencies (N, n) and percentages (%). Quantitative variables were presented as means ± standard deviations (SD). The Kruskal-Wallis rank sum test, Pearson’s chi-squared test, Fisher’s exact test, one-way ANOVA, and Duncan’s post hoc test were conducted to explore associations and make comparisons. For these tests, the confidence interval for the null hypothesis was set at 95%, with a significance threshold of 5% (p-value significant if p < 0.05).

The results of this study highlight a significant variation in body composition parameters based on T2D risk levels, emphasizing their critical role in the pathogenesis and prediction of diabetes. These findings confirm the importance of monitoring and intervening on these parameters to prevent T2D.

Body mass index (BMI) was significantly higher in patients at risk of T2D within 10 years (34.3 ± 3.6 kg/m²), consistent with previous studies establishing a direct link between obesity and T2D [18] [19] . Excess body fat, particularly visceral fat, promotes chronic inflammation and releases inflammatory cytokines (such as TNF-α and IL-6), which disrupt insulin signaling and contribute to insulin resistance [20] [21] .

Muscle mass, on the other hand, was highest in non-diabetic individuals (36 ± 6 kg) and lowest in the increased-risk group (22 ± 2 kg). This can be explained by the role of skeletal muscles as the primary sites for glucose uptake under insulin stimulation [22] [23] . Reduced muscle mass decreases this uptake, exacerbating hyperglycemia and increasing T2D risk [24] .

Bone mass was significantly higher in the increased-risk group (3.15 ± 0.51 kg), which may seem paradoxical. However, some studies suggest that higher bone mass levels might be associated with metabolic alterations due to insulin resistance in bones, affecting bone formation and remodeling [25] .

The percentage of body water was highest in non-diabetic individuals (49.0% ± 6.7%), reflecting better hydration and a more balanced body composition. Patients in the increased-risk group had lower values, suggesting altered body fluids, often observed in individuals with excess body fat or inflammation [26] .

Body fat percentage was highest in the increased-risk group (52% ± 4%). A high proportion of body fat, especially visceral fat, is a key factor in T2D development. It disrupts metabolic balance by releasing free fatty acids and inflammatory mediators that exacerbate insulin resistance [27] .

Finally, visceral fat was significantly higher in the increased-risk group (13.7 ± 3.9 kg) and in patients at risk of T2D within 10 years (13.1 ± 1.1 kg). Visceral fat is particularly harmful as it is metabolically active and directly associated with the risk of metabolic diseases, including T2D [28] . Excessive visceral fat accumulation promotes hyperinsulinemia and elevated blood glucose levels.

Clinically, these patterns support low-cost, scalable actions that target visceral adiposity reduction and preservation of lean mass: enroll high-risk adults in structured lifestyle programs delivering ≥150 min/week of moderate aerobic activity plus ≥2 weekly resistance-training sessions, pair this with a calorie-controlled, high-fiber eating pattern, and integrate FINDRISC with routine waist-circumference and BIA tracking every 3 - 6 months to trigger referral to prevention programs; address sleep and smoking cessation; and, for very-high-risk individuals with persistent dysglycemia, consider metformin as per ADA prevention guidance (individualized) [29] - [31] . These steps are aligned with international recommendations and feasible in resource-limited primary care [31] [32] .

To situate these results in the African context, recent data from Uganda (2023) and South Africa (2024) show that BIA-derived adiposity—especially visceral fat—and lower total body water are associated with type 2 diabetes or higher cardiometabolic risk, reinforcing the value of monitoring body composition alongside BMI in Sub-Saharan Africa [29] [30] .

Our findings underscore the importance of monitoring body composition parameters as indicators of T2D risk. Proactive management, including interventions targeting BMI, muscle mass, and visceral fat reduction, could significantly lower the incidence of T2D, particularly in high-risk populations.

Our study was reviewed and approved by the Institutional Ethics Committee of Douala Gynaeco-Obstetric and Pediatric Hospital (N˚2024/1626/HGOPED/DG/CEI). Written informed consent for participation in this study was obtained from each participant. Given that our study involved experiments on human subjects and/or the use of human tissue samples, we confirm that all experiments were conducted in accordance with applicable guidelines and regulations.

The data used in this study can be made available upon request by the reviewers.

The authors declare that the research was conducted without external funding.

Noël Désirée Mbango-Ekouta and Wilfried Steve Ndeme Mboussi conceptualized the study, designed the experimental approach, and developed the writing plan. Noël Désirée Mbango-Ekouta, Vanessa Ngo Bikai and Sandrine Ongnessek were responsible for participant recruitment and laboratory analyses. Statistical analysis was performed by Wilfried Steve Ndeme Mboussi. Noël Désirée Mbango-Ekouta drafted the initial manuscript, while Sandrine Ongnessek and Jacques Narcisse Doumbe critically reviewed and revised it. All authors made substantial, direct, and intellectual contributions to the work and approved the final version of the manuscript for publication.

We extend our thanks to all the patients who voluntarily agreed to participate in the study.