Dr. Ron’s Research Review – August 6, 2014

© 2014

This week’s research review focuses on tinnitus and hyperinsulinism.
The history of neurootology and the history of diabetes mellitus have their earliest but separate recognition in ancient Egyptian medicine. Both the polyuric condition resembling diabetes and "humming in the ear" now known as tinnitus were described. The hyperinsulinemia associated with idiopathic tinnitus, vertigo, and hearing loss and the hyperinsulinemia of NIDDM, without regard for glycemia status, are one and the same entity. The merging relationship preceded the clinical recognition of both entities. (Kraft, 1995) (Kraft, 1998)
48 patients (25 woman, mean age 42 +/- 9.9 years and 23 men, mean age 46.6 +/- 8.3 years) suffering from vertigo, tinnitus and hearing loss of unknown origin were included into this study. The occurrence of hyperinsulinemia was significantly more common in the patients group--43.8%, comparing to the control group--22.6%. Also the insulin levels in the second hour of OGTT, were statistically significantly higher in patients that in the control group. (Doroszewska and Kazmierczak, 2002)
One study compared 48 patients suffering from vertigo, tinnitus, or hearing loss of unknown origin with 31 control subjects. Disturbances of glucose metabolism were found in 27.1% of patients but in only 9.7% of controls. Diabetes mellitus was not present in any controls but was identified in four patients. Hyperinsulinemia was almost twice as common in patients as in controls.(Kazmierczak and Doroszewska, 2001)
The likelihood of improving tinnitus symptoms was fivefold higher in hyperinsulinemic patients who followed the diet than in those who did not (RR, 5.34; 95% CI, 1.85-15.37; p < .05). In addition, resolution of tinnitus was reported by 15% of the patients who followed the diet as compared to 0% of those who did not. (Lavinsky et al., 2004)

 

Dr. Ron


 

Articles

Metabolic disorders in vertigo, tinnitus, and hearing loss
            (Kazmierczak and Doroszewska, 2001) Download
Vertigo, tinnitus, and hearing loss are common complaints among populations of industrial countries, especially in persons older than 40 years. Numerous agents are known to incite vertigo, tinnitus, and hearing loss, among them hyperinsulinemia, diabetes mellitus, and hyperlipidemia. In this study, we proposed to assess the occurrence of hyperinsulinemia, diabetes mellitus, and hyperlipidemia in patients suffering from vertigo, tinnitus, or hearing loss of unknown origin. Results of various tests in 48 patients were compared to those in 31 control subjects. Assessments of body mass index, blood pressure, and laryngological, audiometric, and electronystagmographic parameters were performed in all study participants. An oral glucose tolerance test was used to evaluate insulin levels, and lipoprotein phenotyping served to determine cholesterol, triglyceride, and lipoprotein levels. Patients were found to be significantly more overweight (on the basis of body mass index) than were the control subjects. Hypertension was more common among patients than controls, but the difference was significant only between the men in the two groups. Disturbances of glucose metabolism were found in 27.1% of patients but in only 9.7% of controls. Diabetes mellitus was not present in any controls but was identified in four patients. Hyperinsulinemia was almost twice as common in patients as in controls. Only the occurrence of hyperlipoproteinemia seemed not to differ between patients and control subjects. We conclude that such disturbances of glucose metabolism as diabetes mellitus and hyperinsulinemia may be responsible for inner ear diseases, whereas the role of disturbances of lipid metabolism remains vague.

Hyperinsulinemia: The Common Denominator of Subjective Idiopathic Tinnitus and Other Idiopathic Central and Peripheral Neurootologic Disorders
            (Kraft, 1995) Download
Hyperinsulinemia as determined by glucose/insulin tolerance identified an etiologic relationship to idiopathic Meniere's disease. This was subsequently concurred with internationally by others. Proctor identified hyperinsulinemia in Subjective Idiopathic Tinnitus (SIT). Hyperinsulinemia and migraine with tinnitus and/or vertigo were also correlated.


 

Hyperinsulinemia: A Merging History with Idiopathic Tinnitus, Vertigo, and Hearing Loss
         (Kraft, 1998) Download
The history of neurootology and the history of diabetes mellitus have their earliest but separate recognition in ancient Egyptian medicine. Both the polyuric condition resembling diabetes and "humming in the ear" now known as tinnitus were described. Yallow's refinement of a radioimmunoassay for insulin demonstrated increased insulin (hyperinsulinemia) in known diabetics. Glucose-insulin tolerances corroborated Yallow's findings. Specific hyperinsulinemia patterns of non-insulin-dependent diabetes mellitus, type II (NIDDM) have been identified. Hyperinsulinemia precedes hyperglycemia. Hyperinsulinemia with normal glucose tolerance is the earliest identifier of NIDDM. In 1977, Updegraff identified hyperinsulinemia with idiopathic Meniere's disease. Sustained clinical response was achieved in all who maintained nutritional management. This finding was the first major impact of hyperinsulinemia in the clinical arena. Subsequently, Updegraff's studies were substantiated by others. As a result, the clinical pathology of hyperinsulinemia has become a major factor in multiple medical disciplines. The hyperinsulinemia associated with idiopathic tinnitus, vertigo, and hearing loss and the hyperinsulinemia of NIDDM, without regard for glycemia status, are one and the same entity. The merging relationship preceded the clinical recognition of both entities. A retrospective relationship to ancient Egyptian medicine and before is considered to be most probable.

Hyperinsulinemia and tinnitus: a historical cohort
         (Lavinsky et al., 2004) Download
Tinnitus affects millions of people worldwide, and it signals the presence of several underlying diseases, including hyperinsulinemia. The aim of this study was to evaluate the response to dietary treatment in 80 patients with associated tinnitus and hyperinsulinemia. On the basis of data obtained by a questionnaire, two groups were established: One included patients who followed the prescribed diet; the other group included patients who did not comply with the treatment. The likelihood of improving tinnitus symptoms was fivefold higher in hyperinsulinemic patients who followed the diet than in those who did not (relative risk [RR], 5.34; 95% confidence interval [CI], 1.85-15.37; p < .05). In addition, resolution of tinnitus was reported by 15% of the patients who followed the diet as compared to 0% of those who did not. These findings underscore the importance of including hyperinsulinemia in the routine diagnostic investigation of patients with tinnitus regardless of whether associated with neurosensory dysacusis or vertigo (or both).

 

References

Doroszewska, G. and H. Kazmierczak (2002), ‘[Hyperinsulinemia in vertigo, tinnitus and hearing loss]’, Otolaryngol Pol, 56 (1), 57-62. PubMedID: 12053670
Kazmierczak, H. and G. Doroszewska (2001), ‘Metabolic disorders in vertigo, tinnitus, and hearing loss’, Int Tinnitus J, 7 (1), 54-58. PubMedID: 14964957
Kraft, J. R. (1995), ‘Hyperinsulinemia: The Common Denominator of Subjective Idiopathic Tinnitus and Other Idiopathic Central and Peripheral Neurootologic Disorders’, Int Tinnitus J, 1 (1), 46-53. PubMedID: 10753320
——— (1998), ‘Hyperinsulinemia: A Merging History with Idiopathic Tinnitus, Vertigo, and Hearing Loss’, Int Tinnitus J, 4 (2), 127-30. PubMedID: 10753400
Lavinsky, L., et al. (2004), ‘Hyperinsulinemia and tinnitus: a historical cohort’, Int Tinnitus J, 10 (1), 24-30. PubMedID: 15379344