Persons with chronic primary autonomic failure and widespread sympathetic denervation and postural hypotension often have postprandial hypotension (Mathias 1991). Food consumption often exacerbates symptoms and the degree of postural hypotension in certain groups. The cardiovascular responses to food ingestion in individuals with tetraplegia have been investigated.
| Author Year Country | Methods | Outcomes |
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Baliga et al. 1997 USA Prospective Controlled Trial N=11
| Population: Tetraplegia (N=6): Mean age=33 yr; Gender: males=6, females=0; Severity of injury: complete; Paraplegia (N=5): Mean age=36 yr; Gender: males=4, females=1; Severity of injury: complete. Intervention: Individuals with tetraplegia received a milk-based liquid meal including Compan and glucose supplements (66 g carbohydrates, 22 g fat, 18 g protein, 550 Kcal, 300 mL). Individuals with paraplegia served as controls. Outcome Measures: Blood pressure [mean arterial (BP), systolic (SBP) and diastolic (DBP)]; plasma noradrenaline and adrenaline levels; heart rate (HR); serum osmolality, renin activity, glucose, and other electrolytes. | 1. Those with tetraplegia had higher basal SBP and HR, but lower basal DBP compared to controls; after the meal, BP decreased in the treatment group (not significant) but not for controls 2. Basal plasma noradrenaline levels were lower for the treatment group compared to the controls; after the meal, the controls group’s plasma noradrenaline levels increased (p<0.05), while the treatment group’s did not. 3. Basal renin activity and glucose level among the treatment group increased after ingestion (p<0.05), but the control group’s did not. 4. HR and all other measures did not change in either group. |
A fall in BP following the ingestion of food has been described in individuals with secondary autonomic failure of various causes. A single study has assessed cardiovascular and hormonal responses to food ingestion among individuals with tetraplegia from cervical spinal cord transection. Baliga et al. (1997) investigated the effects of a standard liquid meal (300 mL total liquid volume, 550 kilocalories, 66 grams carbohydrate, 22 grams fat, 18 grams protein) on BP, HR and neurohormonal levels. Five individuals with paraplegia with complete lesions (T12-L3) and essentially intact sympathetic nervous systems who did not experience postural hypotension served as the control group. The experimental group consisted of six individuals with tetraplegia (C4-7) with chronic and complete cervical spinal cord transection. All had postural hypotension. After food ingestion there was no change in BP or HR in either group. Plasma noradrenaline was unchanged for those with tetraplegia but rose in those with paraplegia. Conversely, plasma renin activity rose among those with tetraplegia but not paraplegia.
There is level 2 evidence (from one prospective controlled trial; Baliga et al. 1997) that consumption of a standard liquid meal does not change blood pressure, heart rate or noradrenalin levels in individuals with tetraplegia and postural hypotension.
Consumption of a standard liquid meal does not change blood pressure, heart rate or noradrenalin levels in individuals with tetraplegia and postural hypotension.
