Nutrition Module

Track nutritional status, dietary patterns, and eating behaviors affecting sleep apnea

Overview

The Nutrition module tracks nutritional assessments and dietary factors that significantly impact sleep apnea severity and treatment outcomes. Obesity is the primary modifiable risk factor for OSA, making nutritional management a critical component of comprehensive care.

Model: Nutricion
Location: apps/exams/models.py:101-148

Weight loss of just 10-15% can reduce AHI by 30-50% in obese patients with OSA. Nutritional interventions complement PAP therapy and may allow some patients to discontinue or reduce therapy intensity.

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Data Fields

Nutritional Status Classification

estado_nutricional · CharField · required

Nutritional Status - BMI-based classification of body weight status

Available Choices:

• DESNUTRICIÓN - Malnutrition (BMI < 18.5)
• EUTRÓFICO - Normal weight (BMI 18.5-24.9)
• SOBREPESO - Overweight (BMI 25-29.9)
• OBESIDAD I - Obesity Class I (BMI 30-34.9)
• OBESIDAD II - Obesity Class II (BMI 35-39.9)
• OBESIDAD III - Obesity Class III (BMI ≥ 40)

Form Label: “Estado Nutricional”

Clinical Significance by Category:

Status	BMI Range	OSA Risk	Management Priority
Desnutrición	< 18.5	Low	Investigate underlying cause, monitor for central apnea
Eutrófico	18.5-24.9	Baseline	Focus on non-weight risk factors (anatomy, position)
Sobrepeso	25-29.9	Moderate	Lifestyle modifications, 5-10% weight loss goal
Obesidad I	30-34.9	High	Structured weight loss program, 10% reduction goal
Obesidad II	35-39.9	Very High	Intensive intervention, consider bariatric referral
Obesidad III	≥ 40	Extreme	Urgent weight management, bariatric surgery candidate

Obesity Class II-III patients often have obesity hypoventilation syndrome (OHS) in addition to OSA, requiring higher BiPAP pressures and close monitoring of CO₂ levels.

Macronutrient Composition

carbohidratos_pct · DecimalField · required

Carbohydrate Percentage - Percentage of daily calories from carbohydrates

• Format: Decimal (5 digits, 2 decimal places)
• Range: 0.00 - 100.00
• Unit: Percentage of total daily calories
• Form Label: “Carbohidratos”
• Typical Ranges:
  • Low-carb: < 30%
  • Moderate: 30-50%
  • High-carb: > 50%

Clinical Relevance:

• High carbohydrate diets (especially refined sugars) promote inflammation and weight gain
• Low-carb diets may improve AHI independent of weight loss
• Mediterranean and ketogenic diets show promise in OSA management
• Carb timing matters: high-carb meals before bed may worsen apnea

Sleep-Related Eating Behaviors

rumiacion · CharField · required

Nocturnal Rumination - Presence of nighttime eating or regurgitation behavior

Available Choices:

• SI - Yes
• NO - No

Form Label: “Rumiación Nocturna” Display Labels:

• SI → “Sí”
• NO → “No”

Clinical Significance:

• Gastroesophageal reflux (GERD) often coexists with OSA
• Nocturnal rumination/regurgitation worsens upper airway obstruction
• Positive pressure therapy can increase gastric air, worsening reflux
• May require proton pump inhibitors (PPIs) or H2 blockers
• Elevating head of bed 30° helps both conditions

Patients with rumination should be evaluated for GERD. Treating reflux can improve CPAP tolerance and reduce residual AHI.

Stimulant Consumption

cafeina · DecimalField · required

Caffeine Consumption - Daily caffeine intake in milligrams

• Format: Decimal (5 digits, 2 decimal places)
• Unit: Milligrams per day (mg/day)
• Form Label: “Consumo de Cafeína”

Reference Values:

Daily Caffeine	Classification	Common Sources
< 100 mg	Low	1 cup coffee or 2 cups tea
100-400 mg	Moderate	1-4 cups coffee (safe for most adults)
> 400 mg	High	4+ cups coffee (may cause issues)
> 600 mg	Excessive	Risk of dependence and sleep disruption

Clinical Relevance:

• Excessive caffeine compensates for OSA-related fatigue
• High intake suggests inadequate OSA treatment or poor sleep quality
• Caffeine use >6 hours before bed worsens sleep architecture
• Reducing caffeine may improve subjective sleep quality
• Decrease in caffeine need is positive treatment outcome indicator

Patients successfully treated for OSA often spontaneously reduce caffeine consumption as their daytime energy improves. Persistently high caffeine use despite good PAP adherence may indicate:

• Residual excessive sleepiness
• Comorbid insomnia
• Inadequate pressure settings
• Other sleep disorders (restless legs syndrome, narcolepsy)

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Relationships

ingreso · ForeignKey

Links to the patient’s active admission record

Related Name: nutriciones
On Delete: CASCADE

registrado_por · ForeignKey

User (nutritionist or clinician) who registered this assessment

Related Name: nutriciones_registradas
On Delete: SET_NULL

created_at · DateTimeField

Timestamp when this nutritional assessment was recorded

Auto-generated: Automatically set on record creation

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Registration Workflow

View: register_nutricion (apps/exams/views.py:153-184)

def register_nutricion(request, patient_id):
    patient = get_object_or_404(Patient, id=patient_id)
    
    # Find patient's active admission (prevents orphaned records)
    ingreso_actual = patient.ingresos.filter(estado='ACTIVO').first()
    
    if request.method == 'POST':
        form = NutricionForm(request.POST)
        if form.is_valid():
            nutricion = form.save(commit=False)
            
            # Link to active admission
            nutricion.ingreso = ingreso_actual
            nutricion.registrado_por = request.user
            
            nutricion.save()
            
            messages.success(
                request,
                f'Consulta de nutrición registrada para {patient.nombre} exitosamente'
            )
            return redirect('patient_clinical', patient_id=patient.id)
    else:
        form = NutricionForm()
    
    return render(request, 'exams/register_nutricion.html', {
        'patient': patient,
        'form': form,
        'ingreso_actual': ingreso_actual
    })

Key Workflow Features

Active Admission Enforcement:

• Nutrition assessments tied to current treatment cycle
• Retrieves ingreso_actual with estado='ACTIVO'
• Enables tracking nutritional changes across treatment phases

Context Variables:

• patient: Patient demographic information
• form: NutricionForm with model field definitions
• ingreso_actual: Current admission record (passed for reference)

This allows the template to display admission-specific information (e.g., admission date, cycle number) alongside the nutrition form.

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Clinical Applications

Obesity and Sleep Apnea

Mechanism

How Obesity Worsens OSA:

• Fat deposits narrow upper airway
• Increased neck circumference
• Reduced lung volume (less tracheal traction)
• Inflammatory adipokines
• Central fat → metabolic syndrome

Evidence

Weight Loss Benefits:

• 10% weight loss → 30% AHI reduction
• 15% weight loss → 50% AHI reduction
• Some patients achieve cure (AHI < 5)
• Improves CPAP adherence
• Reduces cardiovascular risk

Nutritional Interventions

Caloric Restriction (Standard Approach)

Target: 500-1000 kcal/day deficit

Expected Weight Loss: 0.5-1 kg per week

Evidence:

• Most studied approach
• Combined with exercise for best results
• Requires long-term behavior change
• Moderate success rate (30-40% achieve 10% loss)

Challenges: Weight regain common, requires ongoing support

Mediterranean Diet

Composition:

• High in vegetables, fruits, whole grains
• Olive oil as primary fat
• Moderate fish, poultry, legumes
• Low red meat, processed foods

OSA Benefits:

• Anti-inflammatory effects
• Improves AHI beyond weight loss alone
• Cardiovascular protection (important in OSA)
• Better long-term adherence than restrictive diets

Research: Multiple RCTs show 20-30% AHI reduction even with modest weight loss

Low-Carbohydrate/Ketogenic Diet

Composition:

• Very low carbohydrate (< 50g/day for keto)
• High fat (60-75% calories)
• Moderate protein

OSA Benefits:

• Rapid initial weight loss (motivating)
• Reduces inflammation
• May improve AHI independent of weight
• Reduces insulin resistance

Considerations:

• Difficult to maintain long-term
• May affect lipid profile (monitor)
• “Keto flu” initial side effects
• Not suitable for all patients

Bariatric Surgery (Severe Obesity)

Indications:

• BMI ≥ 40 (Obesity Class III)
• BMI ≥ 35 with serious comorbidities (including severe OSA)
• Failed conservative weight loss attempts

OSA Outcomes:

• Average AHI reduction: 60-70%
• Complete OSA resolution: 30-40% of patients
• Allows CPAP discontinuation or pressure reduction
• Dramatic improvement in quality of life

Considerations:

• Perioperative risk (OSA complicates anesthesia)
• Requires lifelong nutritional monitoring
• Best outcomes with Roux-en-Y gastric bypass
• Should be discussed with all Class III obesity patients

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Dietary Patterns and Sleep

Problematic Eating Behaviors

Late-Night Eating

Issue: Meals within 3 hours of bedtime worsen OSA

Mechanisms:

• Increased abdominal pressure on diaphragm
• Gastroesophageal reflux
• Supine position with full stomach
• Altered sleep architecture

Recommendation: Last meal at least 3 hours before bed; light snacks only if needed

High-Carbohydrate Evening Meals

Issue: Refined carbs before bed may worsen apnea

Mechanisms:

• Rapid insulin spike → reactive hypoglycemia
• Inflammation from glycemic variability
• Increased sympathetic nervous system activity

Recommendation: Low-glycemic evening meals; emphasize protein and healthy fats

Alcohol Consumption

Issue: Alcohol significantly worsens OSA (not tracked in this model but should be assessed)

Mechanisms:

• Relaxes upper airway muscles
• Suppresses arousal responses
• Worsens oxygen desaturation
• Dose-dependent effect

Recommendation: Avoid alcohol within 4-6 hours of sleep; educate all OSA patients

Gastroesophageal Reflux and Rumination

Bidirectional Relationship:

• OSA → GERD: Negative intrathoracic pressure during apneas pulls stomach contents into esophagus
• GERD → OSA: Acid reflux causes laryngeal edema and increased airway resistance
• CPAP can worsen GERD by pushing air into stomach (especially high pressures)

Management:

1. Proton pump inhibitors (PPIs) or H2 blockers
2. Avoid trigger foods (spicy, fatty, acidic)
3. Elevate head of bed 30° (helps both GERD and OSA)
4. No eating 3 hours before bed
5. Consider EPR (expiratory pressure relief) on CPAP to reduce gastric air

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Tracking Nutritional Progress

Serial Assessment Strategy

Baseline (Admission):
→ Document nutritional status, carb intake, rumination, caffeine
→ Set weight loss goals (if appropriate)
→ Identify dietary risk factors

Month 1-3 (Early Treatment):
→ Monitor dietary adherence
→ Track weight changes
→ Assess if nutritional interventions needed
→ Correlate diet with PAP adherence

Month 3-6 (Consolidation):
→ Evaluate weight loss progress
→ Adjust nutritional status classification
→ Celebrate successes (reduced caffeine need is positive!)
→ Address barriers to dietary change

Ongoing (Maintenance):
→ Quarterly assessments
→ Prevent weight regain
→ Reinforce healthy behaviors
→ Consider bariatric referral if Obesity II-III persists

Key Performance Indicators

Weight Trajectory

Target: 5-10% reduction in first 6 months

Track progression through nutritional status categories (e.g., Obesity III → Obesity II)

Caffeine Reduction

Target: 25-50% decrease from baseline

Indicates improved daytime alertness from successful OSA treatment

Rumination Resolution

Target: “NO” after GERD treatment

Improves PAP tolerance and reduces residual AHI

Dietary Quality

Target: Moderate carb intake (30-50%)

Shift from high-carb/processed to balanced/whole foods

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Data Retrieval

View: patient_clinical (apps/exams/views.py:30)

# Get all nutrition sessions for active admission
sesiones_nutricion = Nutricion.objects.filter(
    ingreso=ingreso_actual
).order_by('-id')

Nutrition assessments are filtered by the patient’s active admission and ordered by ID (most recent first) to track dietary changes over time and correlate with weight loss progress.

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Related Modules

Polysomnography

AHI severity guides weight loss urgency

Monitoring

Weight loss improves residual AHI

Psychology

Emotional eating and weight management barriers