Evaluation of Nutritional Status Using Anthropometry and Biochemical Indices of CommunityDwelling Older Persons in Nigeria

The ageing population in Nigeria is rapidly increasing, and with it comes a heightened risk of malnutrition, chronic disease, and functional decline. Accurate assessment of nutritional status is essential for developing targeted interventions, allocating resources, and improving the quality of life of older adults. This page summarises the key concepts, methods, and findings from recent studies that have applied anthropometric and biochemical tools to evaluate nutrition among communitydwelling elderly Nigerians.

Why Nutritional Assessment Matters for Older Adults

• Physiological changes: Reduced appetite, altered taste, sarcopenia, and decreased absorption affect nutrient intake and utilization.
• Socioeconomic factors: Poverty, limited market access, and reliance on traditional diets can predispose older people to deficiencies.
• Health impact: Malnutrition is linked to increased morbidity, longer hospital stays, higher mortality, and reduced independence.

Anthropometric Methods

Anthropometry provides noninvasive, inexpensive, and easytoapply measures that reflect body composition and growth patterns. The most commonly used indicators in Nigerian studies include:

1. Body Mass Index (BMI)

Calculated as weight (kg) divided by height squared (m). WHO cutoffs are applied, but for older adults, a BMI of 2227kg/m is often considered optimal to offset the risk of frailty.

2. MidUpper Arm Circumference (MUAC)

Measured at the midpoint between the acromion and olecranon. MUAC <23cm typically indicates undernutrition, while >33cm suggests overweight.

3. Calf Circumference (CC)

Reflects muscle mass; a CC <31cm is associated with sarcopenia and functional impairment.

4. Skinfold Thickness

Triceps skinfold (TSF) helps estimate subcutaneous fat. Equations such as the DurninWomersley method are used to convert TSF into body fat percentage.

Biochemical Indices

Laboratory markers complement anthropometry by revealing metabolic and micronutrient status. Frequently measured indices in the Nigerian context are:

1. Serum Albumin

Indicator of protein status and inflammation; values <35g/L suggest chronic malnutrition.

2. Hemoglobin and Hematocrit

Assess irondeficiency anemia; WHO defines anemia in older adults as Hb <12g/dL (women) or <13g/dL (men).

3. Serum Micronutrients

VitaminD, B12, folate, and zinc levels are often low due to limited sunlight exposure, dietary inadequacy, or malabsorption.

4. CReactive Protein (CRP)

Elevated CRP (>5mg/L) indicates inflammation, which can confound the interpretation of albumin and other nutritional biomarkers.

Integrating Anthropometric and Biochemical Data

Combining fieldfriendly anthropometric measures with selective laboratory tests provides a comprehensive picture of nutritional health. The Mini Nutritional Assessment (MNA) and the Subjective Global Assessment (SGA) are often adapted to include these objective markers, improving predictive accuracy for adverse outcomes.

Key Findings from Recent Nigerian Studies

All studies used locally calibrated cutoffs where appropriate, acknowledging ethnic variations in body composition.

Challenges in the Nigerian Context

• Resource constraints: Limited laboratory capacity makes routine biochemical screening difficult in remote areas.
• Cultural factors: Stigma around aging and reliance on traditional healers can delay professional assessment.
• Data gaps: Few longitudinal studies exist; most data are crosssectional, limiting causal inference.

Recommendations for Practice

1. Screening protocol: Use MUAC and calf circumference as firstline tools in community outreach; follow up abnormal results with targeted labs (albumin, hemoglobin, vitaminD).
2. Capacity building: Train community health workers in standardized anthropometry and interpretation of basic biochemical results.
3. Integrate nutrition into primary care: Embed nutritional assessment into routine chronic disease visits (e.g., hypertension, diabetes).
4. Nutrition education: Promote proteinrich diets (eggs, legumes, fish) and vitaminD sources (fortified foods, safe sunlight exposure).
5. Policy support: Advocate for inclusion of older adults in national nutrition surveillance and budget allocations for basic laboratory services.

Future Research Directions

To refine assessment and intervention:

• Develop populationspecific reference values for MUAC, calf circumference, and skinfold thickness.
• Explore pointofcare devices for rapid measurement of micronutrients (e.g., fingerstick vitaminD tests).
• Conduct longitudinal cohort studies to link baseline nutritional status with outcomes such as disability, hospitalization, and mortality.
• Evaluate communitybased nutrition supplementation programs using mixedmethods designs to capture cultural acceptability.

Conclusion

Anthropometric measurements, when combined with selected biochemical indices, offer a practical and comprehensive approach to assessing the nutritional status of communitydwelling older adults in Nigeria. Despite logistical challenges, scalable screening protocols can be implemented through primary health care networks, ultimately reducing the burden of malnutrition and enhancing healthy ageing across the nation.