TYPE 1 DIABETES CLUSTER INVESTIGATION: 
WESTON, WELLESLEY AND NEWTON
Wayland Great Presenter Series 2011-2012
Wayland Public Library
November 1, 2011

Suzanne K. Condon, Associate Commissioner
Director, Bureau of Environmental Health
Massachusetts Department of Public Health

Outline

I.	Introduction to the Bureau of Environmental Health 

II.	Massachusetts Pediatric Diabetes Surveillance

III.	Type 1 Diabetes in Massachusetts and Selected Communities

IV.	MDPH Investigation of Type 1 Diabetes in Weston, Wellesley, and Newton

V.	Risk Factors for Diabetes

VI.	Autoimmune Diseases and Environmental Exposures

VII.	Next Steps Related to Investigating Diabetes in Weston, Wellesley and Newton

VIII.	Questions

I. Introduction to the Bureau of Environmental Health
•	The Bureau of Environmental Health has a broad mission of protecting the public health from a variety of environmental exposures. The Bureau responds to environmental health concerns and provides communities with epidemiologic and toxicological health assessments.

•	The Bureau comprises nine programs. 

•	The Bureau also ensures regulatory compliance related to food and radiation safety, as well as the state sanitary code.

I. Introduction to the Bureau of Environmental Health 
•	Indoor Air Quality Program
•	Community Assessment Program
•	Environmental Epidemiology Program
•	Environmental Toxicology Program
•	Environmental Health Education and Outreach Program
•	Community Sanitation Program
•	Food Protection Program
•	Radiation Control Program
•	Childhood Lead Poisoning and Prevention Program

I. Introduction to the Bureau of Environmental Health
How do we evaluate health?
•	Assess the potential impact of exposure on the population

•	Evaluate disease frequency in the population

•	Investigate possible associations between exposure and disease

II. Massachusetts Pediatric Diabetes Surveillance
•	Funded through the U.S. Centers for Disease Control and Prevention’s Environmental Public Health Tracking program

•	Coupled with pediatric asthma surveillance

•	Previous verification effort resulted in 97% agreement between school reports and child’s medical record

•	Mailed survey to 2100 public and private school nurses/administrative staff 

•	2008-2009 response rate 99.5% 

II. Massachusetts Pediatric Diabetes Surveillance
•	Prevalence of Type 1 in MA students in grades K-8 is 253 per 100,000 students 

•	Nationally, the prevalence of Type 1 among individuals 5-14 year of age is 214 per 100,000 (from the SEARCH for Diabetes in Youth study)

•	Counts are provided by type of diabetes (Type 1, Type 2, Unknown Type), race/ethnicity, grade, gender, and community of residence

II. Massachusetts Pediatric Diabetes Surveillance 
Type 1 Diabetes in K-8 Students for the 2008-2009 School Year in Massachusetts
•	Children with Type 1 diabetes represented 93% of cases (n=1,761)

•	Children with Type 2 diabetes = 6% (n=111)

•	Unknown type was 1% (n=18)

II. Massachusetts Pediatric Diabetes Surveillance 
Type 1 Diabetes in K-8 Students for the 2008-2009 School Year in Massachusetts
•	Although the national prevalence is lower than the MA rate, the methods for determining the rates were very different and could account for some of the difference

•	SEARCH estimates are based on a sample of individuals (0-19 years of age) who participate in their study

•	MDPH estimates are based on school health information for all children who attend grades K-8 (approximately 5-14 year olds) in public and private schools in MA

III. Type 1 Diabetes in Massachusetts and Selected Communities
Image of map of Selected Communities in Massachusetts
Acton, Concord, Maynard, Sudbury, Wayland, Lincoln, Waltham, Weston, Framingham, Natick, Wellesley, Newton

III. Type 1 Diabetes in Massachusetts and Selected Communities
Prevalence Estimates and their Interpretation 
•	Prevalence estimates are calculated by dividing the number of children with type 1 diabetes in a community by school enrollment totals for that community

•	95% Confidence Intervals (CI) are calculated for each community to measure:
–	Statistical significance (overlapping CI)
–	Stability of the prevalence estimate (width of the CI)

III. Type 1 Diabetes in Massachusetts and Selected Communities
Prevalence of Type 1 Diabetes in K-8 Students for the 2008-2009 School Year in Selected Communities in Massachusetts 

City/Town† 	Number of Students with Type 1 Diabetes 	Total Enrollment 	Prevalence* 	Lower 95% Confidence Interval 	Upper 95% Confidence Interval 	Statistical Significance 	
ACTON 	11 	3420 	322 	160 	576 	Not Statistically Significantly Different 	
CONCORD 	10 	2077 	481 	231 	886 	Not Statistically Significantly Different 	
FRAMINGHAM 	16 	6403 	250 	143 	405 	Not Statistically Significantly Different 	
LINCOLN 	NS 	NS 	NS 	NS 	NS 	NS 	
MAYNARD 	NS 	NS 	NS 	NS 	NS 	NS 	
NATICK 	9 	3909 	230 	105 	437 	Not Statistically Significantly Different 	
NEWTON 	22 	9261 	238 	138 	337 	Not Statistically Significantly Different 	
SUDBURY 	11 	3097 	355 	177 	636 	Not Statistically Significantly Different 	
WAYLAND 	4 	1869 	214 	58 	548 	Not Statistically Significantly Different 	
WELLESLEY 	13 	4237 	307 	163 	525 	Not Statistically Significantly Different 	
WESTON 	7 	1829 	383 	153 	788 	Not Statistically Significantly Different 	
STATEWIDE 	1761 	696105 	253 	241 	265 	‐‐	
† City/Town refers to city/town of the child’s residence
*per 100,000 students
NS--Data not shown due to small numbers

IV. MDPH Investigation of Type 1 Diabetes in Weston, Wellesley and Newton
Selected Massachusetts Communities
Image of map of Selected Communities in Massachusetts - Weston, Wellesley, Newton

IV. MDPH Investigation of Type 1 Diabetes in Weston, Wellesley and Newton 
Prevalence of Type 1 Diabetes in K-8 Students for the 2008-2009 School Year in Weston, Wellesley and Newton, Massachusetts 
City/Town†	Number of Students with Type 1 Diabetes	Total Enrollment	Prevalence*	Lower 95% Confidence Interval	Upper 95% Confidence Interval	Statistical Significance	

NEWTON	22	9261	238	138	337	Not Statistically Significantly Different	
WELLESLEY	13	4237	307	163	525	Not Statistically Significantly Different	
WESTON	7	1829	383	153	788	Not Statistically Significantly Different	
STATEWIDE	1761	696105	253	241	265	---	
† City/Town refers to the city/town of the child's residence	
* per 100,000 students	
NS--Data not shown due to small numbers	

IV. MDPH Investigation of Type 1 Diabetes in Weston, Wellesley and Newton
Environmental Epidemiologic Questions 
1.	Does the prevalence of type 1 diabetes in these 3 communities or the census tracts of concern differ from the expected prevalence?
•	Compare to national SEARCH Study prevalence estimates

2.	Does family history play more of a role in the observed prevalence in the 3 communities or the census tracts of concern than would be expected?
•	Ten percent of individuals diagnosed with type 1 diabetes have a family history of diabetes (Source: Juvenile Diabetes Research Foundation)

3.	Does residential history play a role in the observed prevalence?
•	Did children/adolescents reside in the 3 communities at diagnosis or within 1-2 years prior to diagnosis?

4.	Does the geographic distribution of residence at diagnosis appear unusual?
•	Compare to population density patterns

5.	Is there a grouping of diagnoses in space or time such that it is plausible that a common exposure might have contributed to diagnoses?

IV. MDPH Investigation of Type 1 Diabetes in Weston, Wellesley and Newton
Data Sources 
•	In 2007-2008 MDPH began collecting diabetes data from school health records.
–	As with pediatric asthma, data are reported by school nurses and/or administrative staff at public and private schools in Massachusetts.

•	Family Educational Rights and Privacy Act of 1974 (20 U.S.C. 1232g)
–	Protects students’ privacy for educational records/cannot be released without parental consent
–	Applies to all educational institutions that receive funds from U.S. Dept of Education
–	Applies to entire content of the student’s record

•	In 2009-2010, MDPH worked with school nurse leaders in the three communities to coordinate mailings to all parents of children diagnosed with diabetes

•	In 2010, MDPH contacted health care providers to identify all children in the three communities with type 1 diabetes in an effort to capture information about:
–	Pre-school age children  
–	Those attending private schools outside Weston, Wellesley, and Newton

IV. MDPH Investigation of Type 1 Diabetes in Weston, Wellesley and Newton
Consent Form
–	Residential History
–	Family History
–	Insulin dependency
–	Age at diagnosis

IV. MDPH Investigation of Type 1 Diabetes in Weston, Wellesley and Newton
Selected Census Tracts in Weston, Wellesley and 
Newton Massachusetts 
Image of map of Selected Census Tracts in Weston, Wellesley, Newton
Massachusetts

V.  Risk Factors for Diabetes
•	Type 1 diabetes is thought to be autoimmune in nature, for that reason environmental factors are also thought to play a role; genetic factors and a family history are also thought to play a role in the development of Type 1

•	Type 2 diabetes also has some suggested environmental risk factors including persistent organic pollutants (e.g. PCBs)

•	Recognized risk factors for Type 2 include family history, obesity, physical inactivity, race/ethnicity and others

V.  Risk Factors for Diabetes
Potential Environmental Risk Factors Associated with Type 1 Diabetes
Class	Specific agent	
Viruses	Enteroviruses
Rubella (congenital)
Coxsackie B
Rotaviruses	
Nutritional	Cow’s milk and cow’s milk-based infant formula
Gluten
Exposure to Bafilomycin A1
Nitrates (N-nitroso compounds)
Vitamin D Deficiency	
Life-style / Other	Exposure to b-cell toxins (e.g. the rat poison, Vacor)
Smoking (Family members, indoors)
Older maternal age
Birth order
Infant Growth
Birth weight
Stressful life events	
*Based on Table 2 from Zvi Laron’s Interplay Between Heredity and Environment in the Recent Explosion of Type 1 Childhood Diabetes Mellitus	

V.  Risk Factors for Diabetes
Other Potential Risk Factors for Type 1 Diabetes Requiring Further Study
•	Exposure to ozone, sulfates, and particulate air pollution
–	One study in California has shown an association between estimates of exposure to air pollution and type 1 diabetes

•	Exposure to persistent organic pollutants
–	Conflicting results in the few studies that have been conducted
–	Studies have major limitation (e.g. cross-sectional design unable to report whether diabetes or higher PCB levels came first)

VI. Autoimmune Disease and Environmental Exposures 
The Development of Type I Diabetes

Genetic Predisposition	
	
Immunologic Trigger/Environmental Event	
	
Autoimmune Response	
	
Insulin Release Impaired	
	
Reduction in Beta Cell Mass	
	
Type I Diabetes	

*Adapted from Figure 338-6 in Diabetes Mellitus in Harrison’s Principles of Internal Medicine, 17th Edition (2008)

VI. Autoimmune Disease and Environmental Exposures
•	Literature suggests that petroleum distillates (products, such as diesel fuel created from processing crude oil), mercury, silica and chlorinated hydrocarbons may be associated with lupus and other undifferentiated connective tissue diseases

VI. Autoimmune Disease and Environmental Exposures
Density of Tier-Classified 21e Sites with Lupus-Suspected Chemicals and Neighborhoods with the Highest Rates of Lupus
Image of map of Boston, Massachusetts showing the neighborhoods with the highest rates of Lupus and the density of Tier-Classified 21e Sites with Lupus-Suspected Chemicals 

VII. Next Steps Related to Investigating Diabetes in Weston, Wellesley & Newton
•	MDPH will soon release a report summarizing the 3-community prevalence estimates to residents of Weston, Wellesley, and Newton (expected in December 2011)

•	The report will also review smaller geographic areas within the 3 communities to determine if prevalence is higher in certain areas

•	MDPH will then complete review of environmental sites in the 4 census tracts to evaluate in relation to disease prevalence

•	The findings of these reports will best direct follow-up investigative efforts

VIII. Questions?