Effects of sodium intake on postural lightheadedness: Results from the DASH-sodium trial.

Lightheadedness after standing contributes to adverse clinical events, including falls. Recommendations for higher sodium intake to treat postural lightheadedness have not been evaluated in a trial setting. The Dietary Approaches to Stop Hypertension (DASH)-Sodium trial (1998-1999) tested the effects of the DASH diet and sodium reduction on blood pressure (BP). Participants were randomly assigned to DASH or a typical Western diet (control). During either diet, participants ate three sodium levels (50, 100, 150 meq/d at 2100 kcal) in random order for 30-days, separated by 5-day breaks. Participants reported the presence and severity of postural lightheadedness at baseline and after each feeding period. There were 412 participants (mean age 48 years; 57% women; 57% black). Mean baseline SBP/DBP was 135/86 mm Hg; 9.5% reported baseline lightheadedness. Among those consuming the DASH diet, high vs low sodium increased lightheadedness (OR 1.71; 95% CI: 1.01, 2.90; P = 0.047) and severity of lightheadedness (P = 0.02), but did not affect lightheadedness in those consuming the control diet (OR 0.77; 95% CI: 0.46, 1.29; P = 0.32). Among those consuming high vs low sodium in the context of the DASH diet, adults <60 vs ≥60 years old experienced more lightheadedness (P-interaction = 0.04), along with obese vs non-obese adults (P-interaction = 0.01). In the context of the DASH diet, higher sodium intake was associated with more frequent and severe lightheadedness. These findings challenge traditional recommendations to increase sodium intake to prevent lightheadedness.

Postgastric bypass hyperinsulinemic hypoglycemia syndrome: characterization and response to a modified diet.

BACKGROUND: Some alarming cases of hypoglycemic episodes in patients who have undergone Roux-en-Y gastric bypass have been reported. The syndrome of hyperinsulinemic hypoglycemia with nesidioblastosis after Roux-en-Y gastric bypass has been previously reported and is controversial. It has been suggested that subtotal or total pancreatectomy might be needed to control the symptoms in these patients. We have identified a similar cohort of patients with hyperinsulinemic hypoglycemia for whom we have reviewed patient characteristics and measured the glucose and insulin response to mixed meals. METHODS: We reviewed the charts of 14 patients identified by clinic follow-up who reported episodes consistent with hyperinsulinemic hypoglycemia (lightheadedness or loss of consciousness after a high-carbohydrate meal). All patients were given a mixed meal consisting of high carbohydrates on day 1 and a low-carbohydrate meal on day 2. The plasma glucose and serum insulin levels were measured before (fasting) and 30, 60, 90, 120, 150, and 180 minutes after the meal. RESULTS: After a high-carbohydrate meal, 12 of 14 patients demonstrated hyperglycemia associated with hyperinsulinemia at 30 minutes. These patients subsequently became hypoglycemic while the serum insulin was rapidly declining. After reaching a nadir at 120 minutes, the plasma glucose level corrected spontaneously. After a low-carbohydrate mixed meal, the patients demonstrated very little change in plasma glucose and only a modest increase in serum insulin. Of the 12 patients treated with a low-carbohydrate diet, 6 had substantive symptom improvement, and 10 exhibited at least some improvement. CONCLUSION: The hyperinsulinemic hypoglycemia noted in some patients after Roux-en-Y gastric bypass has many similarities to the dumping syndrome. A low-carbohydrate diet successfully improved symptoms in most of our patients. Approaches to treatment should involve a low-carbohydrate diet and alpha-glucosidase inhibitors rather than pancreatectomy.

Migraine-associated dizziness: patient characteristics and management options.

OBJECTIVE: To determine patient characteristics and effectiveness of therapy for migraine-associated dizziness. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary referral center. PATIENTS: Patients were identified through a code query of billing records for the diagnosis of migraine-associated vertigo or disequilibrium, based on the International Headache Society criteria. There were 81 patients (61 women, 20 men) with an average age of 36.6 years (range, 8-71 yr); all except four patients were evaluated between 1995 and 1999. Follow-up was obtained from chart review. Mean follow-up time was 54.5 weeks, with a range of 4 to 456 weeks. INTERVENTION: One or more treatment methods, including dietary manipulation, medication (tricyclic antidepressants, beta-blockers or calcium-channel blockers), and neurology consultation, were applied sequentially as necessary. MAIN OUTCOME MEASURE: Response to therapy was defined as greater than 75% reduction in symptom recurrence rate. RESULTS: Overall, 72% of patients experienced resolution or dramatic reduction of their attacks of vertigo or disequilibrium. Of the 13 patients treated with the introduction of dietary manipulation alone, 100% received significant relief. Of the 31 patients treated with dietary manipulation and the addition of a medication, 77% of these patients had significant relief. Of the final group of 37 patients treated with another medication or a neurology consultation, 57% received substantial relief. Of the responders, the majority (>95%) experienced an equal reduction in both vertigo or disequilibrium and headache symptoms. Interestingly, 100% of the patients in the migraine without active headache group received substantial relief of their vertigo or disequilibrium symptoms with migraine therapy. CONCLUSION: We conclude that there is effective therapy for the common problem of migraine-associated dizziness.