Prevalence, associated factors and clinical outcomes of vitamin B12 deficiency among type 2 diabetic patients on metformin treatment at Bugando Medical Centre, Mwanza, Tanzania
David Mwasota [Male]
Prevalence, associated factors and clinical outcomes of vitamin B12 deficiency among type 2 diabetic patients on metformin treatment at Bugando Medical Centre, Mwanza, Tanzania - Mwanza, Tanzania: Catholic University of Health and Allied Sciences [CUHAS – Bugando] : 2022 - Includes Index
Abstract:
Background: Metformin is a standard therapy, most commonly prescribed oral hypoglycemic drug for individuals with type-2 diabetes mellitus. Despite its usefulness, many studies have documented the association between long-term metformin use and vitamin B12 deficiency among individuals with T2DM. Megaloblastic anemia and worsening of diabetic neuropathy are among the complications accompanying vitamin B12 deficiency. In our setting, the prevalence of vitamin B12 deficiency, associated factors have not been studied.
Objective: To determine the prevalence, associated factors of vitamin B12 deficiency among T2DM patients on metformin treatment at Bugando Medical Centre (BMC).
Methodology: Hospital based cross-sectional study was conducted at BMC’s medical outpatient clinic. A total of 122 T2DM patients were enrolled after meeting inclusion criteria. Structured questionnaires were used to collect patients’ demographic and clinical information. Blood samples were collected for assessing vitamin B12 levels and megaloblastic anemia. Toronto Clinical Neuropathy Score was used to assess sensory peripheral neuropathy with score above 5 indicating presence of peripheral sensory neuropathy. Vitamin B12 deficiency was defined as any value below 200pg/ml. Megaloblastic anemia was Hb of less than 13g/dl in men or less than 12g/dl in female plus mean cell volume above or equal to 100fl with macrocytes/hyper segmented neutrophils on peripheral blood smear. Spearman’s rank correlation coefficient was used to assess the relationship between vitamin B12 and peripheral neuropathy. Multivariable logistic regression was used to determine independent factors associated with vitamin B12 deficiency. Data were analyzed using STATA version 15
Results: 4.1% of diabetic patients had absolute vitamin B12 deficiency, 6.6% had borderline deficiency and 89.3% had normal level among 122 enrollees. Factors associated with vitamin B12 deficiency were metformin dose above 1g/day and alcohol use. None of the study participants had megaloblastic anemia .There was no correlation between vitamin B12 level and sensory neuropathy severity.
Conclusion: Our findings show a low prevalence of vitamin B12 deficiency in type 2 diabetic patients taking metformin. Dose of metformin above 1g/day and alcohol use were associated with vitamin B12 deficiency. Therefore, routine determination of vitamin B12 level in patients with T2DM on at least 1g/day of metformin and consuming alcohol might help in identifying patients that would benefit from vitamin B12 supplementation.
Wurzburg Road 35, BMC Premises, Post Code: 33102: P. O Box 1464, Mwanza – Tanzania: Phone: +255 28 298 3384: Fax: +255 28 298 3386: Email: vc@bugando.ac.tz : Website: www.bugando.ac.tz
--Internal Medicine
Prevalence, associated factors and clinical outcomes of vitamin B12 deficiency among type 2 diabetic patients on metformin treatment at Bugando Medical Centre, Mwanza, Tanzania - Mwanza, Tanzania: Catholic University of Health and Allied Sciences [CUHAS – Bugando] : 2022 - Includes Index
Abstract:
Background: Metformin is a standard therapy, most commonly prescribed oral hypoglycemic drug for individuals with type-2 diabetes mellitus. Despite its usefulness, many studies have documented the association between long-term metformin use and vitamin B12 deficiency among individuals with T2DM. Megaloblastic anemia and worsening of diabetic neuropathy are among the complications accompanying vitamin B12 deficiency. In our setting, the prevalence of vitamin B12 deficiency, associated factors have not been studied.
Objective: To determine the prevalence, associated factors of vitamin B12 deficiency among T2DM patients on metformin treatment at Bugando Medical Centre (BMC).
Methodology: Hospital based cross-sectional study was conducted at BMC’s medical outpatient clinic. A total of 122 T2DM patients were enrolled after meeting inclusion criteria. Structured questionnaires were used to collect patients’ demographic and clinical information. Blood samples were collected for assessing vitamin B12 levels and megaloblastic anemia. Toronto Clinical Neuropathy Score was used to assess sensory peripheral neuropathy with score above 5 indicating presence of peripheral sensory neuropathy. Vitamin B12 deficiency was defined as any value below 200pg/ml. Megaloblastic anemia was Hb of less than 13g/dl in men or less than 12g/dl in female plus mean cell volume above or equal to 100fl with macrocytes/hyper segmented neutrophils on peripheral blood smear. Spearman’s rank correlation coefficient was used to assess the relationship between vitamin B12 and peripheral neuropathy. Multivariable logistic regression was used to determine independent factors associated with vitamin B12 deficiency. Data were analyzed using STATA version 15
Results: 4.1% of diabetic patients had absolute vitamin B12 deficiency, 6.6% had borderline deficiency and 89.3% had normal level among 122 enrollees. Factors associated with vitamin B12 deficiency were metformin dose above 1g/day and alcohol use. None of the study participants had megaloblastic anemia .There was no correlation between vitamin B12 level and sensory neuropathy severity.
Conclusion: Our findings show a low prevalence of vitamin B12 deficiency in type 2 diabetic patients taking metformin. Dose of metformin above 1g/day and alcohol use were associated with vitamin B12 deficiency. Therefore, routine determination of vitamin B12 level in patients with T2DM on at least 1g/day of metformin and consuming alcohol might help in identifying patients that would benefit from vitamin B12 supplementation.
Wurzburg Road 35, BMC Premises, Post Code: 33102: P. O Box 1464, Mwanza – Tanzania: Phone: +255 28 298 3384: Fax: +255 28 298 3386: Email: vc@bugando.ac.tz : Website: www.bugando.ac.tz
--Internal Medicine