What causes an increase in diastolic blood pressure in adults?

What Causes Diastolic Blood Pressure to Increase

Diastolic blood pressure increases primarily due to elevated peripheral vascular resistance, which is driven by obesity, excess sodium intake, physical inactivity, and hormonal factors, particularly in younger adults. 1

Primary Mechanisms of Elevated Diastolic Pressure

Increased Peripheral Vascular Resistance

• Obesity is the dominant modifiable cause of isolated diastolic hypertension (IDH), especially in younger adults, by directly increasing peripheral vascular resistance 1
• Central (abdominal) adiposity specifically elevates diastolic pressure through insulin resistance and adverse metabolic effects 1
• This mechanism explains why IDH occurs predominantly in younger adults (typically <50 years old) and represents an early manifestation of essential hypertension with elevated peripheral resistance 1

Volume and Sodium-Related Factors

• Excess sodium intake directly elevates diastolic pressure by increasing intravascular volume and peripheral resistance 1
• Long-term caloric intake exceeding energy expenditure promotes hypertension development through multiple pathways 1

Lifestyle and Behavioral Causes

• Physical inactivity contributes to IDH through weight gain and increased vascular resistance 1
• Excessive alcohol consumption (more than moderate intake) raises diastolic pressure 1
• Chronic psychosocial stressors contribute through sustained sympathetic activation 1

Secondary and Hormonal Causes

Medication and Hormone-Related

• Oral contraceptive use in women can cause blood pressure elevation, with stroke risk increased 1.4- to 2.0-fold, particularly in older women 2
• Hormonal therapy for infertility may contribute to cardiovascular risk factors including elevated blood pressure 2
• Multiple medications can elevate diastolic pressure, including NSAIDs, systemic corticosteroids, immunosuppressants (cyclosporine), decongestants (phenylephrine, pseudoephedrine), amphetamines, certain antidepressants (MAOIs, SNRIs, TCAs), and recreational drugs 2

Endocrine Disorders

• Primary aldosteronism occurs in 5-10% of patients with hypertension and 20% of those with resistant hypertension, causing toxic tissue effects that induce greater target organ damage than primary hypertension 2
• Mineralocorticoid excess syndromes other than primary aldosteronism present with early-onset hypertension, resistant hypertension, and electrolyte abnormalities 2
• Acromegaly is associated with hypertension through growth hormone excess 2

Sleep and Respiratory Causes

• Sleep apnea is an important secondary cause of diastolic hypertension that must be assessed, though treatment effects on blood pressure have shown mixed results 2, 1

Age-Related Patterns and Clinical Context

Young Adults with IDH

• Isolated diastolic hypertension in young adults (mean age 40 years) occurs predominantly in men with high prevalence of metabolic syndrome 3
• These patients frequently evolve into systolic-diastolic hypertension and are at increased risk for future diabetes and cardiovascular complications 3
• The condition shows genetic susceptibility combined with nutritional-hygienic factors 1

Very Young Adults

• Low DBP with elevated SBP in very young adults (mean age 20 years) results from elevation in stroke volume and/or arterial stiffness, has marked male predominance, and is potentially not benign 3

Important Clinical Pitfalls

Avoid treating based on single measurements: Confirm the diagnosis with repeated measurements on multiple occasions before labeling a patient with isolated diastolic hypertension 1. Out-of-office monitoring (home BP or 24-hour ambulatory monitoring) helps exclude white-coat hypertension 1.

Screen for secondary causes in specific populations: Patients with resistant hypertension, early-onset hypertension, hypokalemia, or adrenal incidentaloma warrant screening for primary aldosteronism using the aldosterone:renin activity ratio 2.

Recognize the metabolic connection: Obesity, insulin resistance, metabolic syndrome, and diabetes mellitus type II are closely associated with increased diastolic pressure and require comprehensive metabolic assessment 2.