Title: Magnesium and the Risk for Type 2 Diabetes Mellitus
1Magnesium and the Risk for Type 2 Diabetes
Mellitus
Risk Assessment Group Seminar
2INTRODUCTION
3Type 2 Diabetes Mellitus
- Definition
- Hyperglycemia resulted from insulin resistance
with an insulin secretory defect - Excess risk for
- Blindness
- Renal failure
- Cardiovascular disease
4Hypomagnesemia in diabetes
- Intracellular magnesium
- Cofactor for enzymes in glucose metabolism
- Maintain tyrosine kinase activity
- at insulin receptor
- Insulin as a regulatory hormone
- Stimulate magnesium uptake by cell
- Insulin receptor-mediated process
5Hypothesis
6Magnesium status in pathogenesis of diabetes
- Serum magnesium
- Dietary intake of magnesium
7Reference 1Serum and Dietary Magnesium and the
Risk for Type 2 Diabetes Mellitus
- The Atherosclerosis Risk in Communities Study
- Arch Intern Med. 19991592151-2159
8PARTICIPANTS AND METHODS
9The Atherosclerosis Risk in Communities Study
- Study design
- Prospective study
- 6 years of follow-up (2 visits)
- Etiology of atherosclerosis and its clinical
sequelae - Participants
- Aged 45-64 years
- Four US communities
- --- Forsyth County, North Carolina
- --- Jackson, Mississippi
- --- Suburbs of Minneapolis, Minnesota
- --- Washington County, Maryland
10Participants
- Exclude
- Ethnicity other than black or white
- Had diabetes at baseline
- Missing exposure or outcome information
- Nonfasting (lt 8 hours)
- Unavailable for follow-up
- Dead
- 10871 participants
11Exposure assessment
- Blood collection
- Fasting ? 12 hrs
- Serum magnesium, glucose level, insulin level,
calcium level, potassium level - Dietary intake
- 61-item food frequency questionnaire (FFQ)
- Mg intake milligrams/4.2 kJ daily energy intake
- Lack of validity study for magnesium
12Outcome assessment
- Diabetes mellitus definition
- Fasting glucose level ? 126 mg/dL
- Non-fasting glucose level ? 200 mg/dL
- Current use of diabetic medication
- Doctor ever told that he/she had diabetes
- Met any of these conditions at visit 2 or visit 3
- ?incident cases of diabetes
13Statistical analysis
- Stratified by race
- Serum Mg level
- Categorized into 6 groups
- Highest level ?0.95 mmol/L (Reference group)
- Dietary Mg intake
- Categorize into quartiles
- Highest quartile as reference group
14Statistical analysis (cont.)
- Statistical significance
- Analysis of variance
- ?2 analysis
- Association between Mg and diabetes
- Logistic regression model
- Odds ratio
15RESULT
16Baseline characteristics (Black)
17Baseline characteristics (White)
18Incidence of type 2 diabetes
19Serum Mg and risk for type 2 diabetes
20Comparison of cross-sectional and prospective
association
Cross-sectional
Prospective
21Dietary Mg Intake
22CONCLUSIONS
23Three main conclusions
- Inverse relationship between serum Mg level and
development of type 2 diabetes - ---White middle-aged adults.
- Cross-sectional relationship
- ---Effect of diabetes on serum Mg level
- No association between dietary Mg intake and
incident type 2 diabetes.
24Dietary Magnesium Intake in Relation to Plasma
Insulin Levels and Risk of Type 2 Diabetes in
Women
Reference 2
- Diabetes Care 2759-65,2004
25RESEARCH DESIGN AND METHODS
26Womens Health Study (WHS)
- Study design
- Randomized, double-blind, placebo controlled
trial - Low-dose aspirin and vitamin E
- Primary prevention of cardiovascular disease and
cancer - Participants
- Aged ? 45 years
- 39876 female health professionals
- Free of coronary heart disease, stroke, and
cancer.
27Assessment of Mg intake
- 131-item SFFQ
- Commonly used unit or portion size
- 9 possible responses
- never 6 or more times per day
- Good validity for magnesium
- SFFQ vs. 2 weeks of diet records
- r 0.76
28Ascertainment of incident type 2 diabetes
- Ask annually about type 2 diabetes diagnosis
- ?
- Questionnaire
- Onset of disease
- Symptoms
- Diagnostic tests
- Hypoglycemic treatment
- ?
- Confirm type 2 diabetes
- Guidelines of the American Diabetes Association
29Assessment of fasting insulin levels
- 349 randomly selected health women
- (Serve as control in WHS)
- Double antibody systems
- --- lt 0.2 cross-reactivity between insulin
- and its precursors
30Data analysis
- Magnesium intake
- --- Categorized into quintiles
- --- Lowest quintile as reference
- Cox proportional hazard model
- ? rate ratio
- Stratified analyses
- by BMI (lt or ? 25 kg/m2)
31Data analysis (cont.)
- Cross-sectional analysis
- Natural logarithm of insulin level
- Multiple linear regression models
- Modifying effect of BMI
- --- Stratified by BMI
32RESULTS
33Baseline characteristics
34RRs of type 2 diabetes
35RRs stratified by BMI
36Plasma fasting insulin level
37Fasting insulin level in two BMI categories
BMI ? 25
38CONCLUSIONS
39For middle-aged women
- risk of
type 2 diabetes - Magnesium intake
- plasma
insulin level - Inverse association
- Significant among overweight (? 25 kg/m2)
- --- Highest quintile had a 22 lower risk
- Beneficial effects
- --- Greater among overweight people
- --- Who are prone to insulin resistance.
40THANKS FOR YOUR ATTENTION!