Urban Heat Exposure as an Emerging Risk Modifier of Type 2 Diabetes Incidence

Databases, interfaces, and search dates We searched from January 1, 2000 through September 12, 2025 (inclusive). Final update (“top-up” search) was September 12, 2025. Source Interface Date run (YYYY-MM-DD) MEDLINE PubMed 2025-09-10 Embase Elsevier 2025-09-10 Web of Science Core Collection (SCI-EXPANDED, SSCI, ESCI) Clarivate 2025-09-11 Scopus Elsevier 2025-09-11 Global Health (CAB Abstracts subset) EBSCO 2025-09-11 CINAHL EBSCO 2025-09-11 African Index Medicus (AIM) WHO IRIS 2025-09-12 AJOL Native 2025-09-12 WHO IRIS (global repository search beyond AIM filter) WHO IRIS 2025-09-12 medRxiv Native 2025-09-12 SSRN Native 2025-09-12 Languages included: English, French, Portuguese.Population: Humans, adults (≥18 y).Region: Sub-Saharan Africa (country list below). Core concepts & SSA country list Heat/temperature concepts: ambient temperature, maximum temperature, minimum/nighttime temperature, apparent temperature / heat index, wet-bulb globe temperature (WBGT), heat wave/heatwave, urban heat island (UHI), thermal exposure. Diabetes concepts: type 2 diabetes (incident/new-onset), dysglycemia, fasting plasma glucose (FPG), HbA1c, hyperglycemic crises, DKA/HHS (as validated acute glycemic outcomes). SSA countries (expanded list used in queries): Angola OR Benin OR Botswana OR Burkina Faso OR Burundi OR Cabo Verde OR Cameroon OR Central African Republic OR Chad OR Comoros OR Congo OR “Congo, Democratic Republic” OR DRC OR Côte d’Ivoire OR Ivory Coast OR Djibouti OR Equatorial Guinea OR Eritrea OR Eswatini OR Ethiopia OR Gabon OR Gambia OR Ghana OR Guinea OR “Guinea-Bissau” OR Kenya OR Lesotho OR Liberia OR Madagascar OR Malawi OR Mali OR Mauritania OR Mauritius OR Mozambique OR Namibia OR Niger OR Nigeria OR Rwanda OR Sao Tome OR “Sao Tome and Principe” OR Senegal OR Seychelles OR “Sierra Leone” OR Somalia OR “South Africa” OR “South Sudan” OR Sudan OR Tanzania OR Togo OR Uganda OR Zambia OR Zimbabwe. Full search strings (verbatim) Note: Each database has its own syntax and subject headings. We combine subject headings (MeSH/Emtree/CINAHL Headings) with free-text in title/abstract/keywords. Date and language limits were applied via interface filters where supported; otherwise embedded in query. MEDLINE (PubMed) (("Diabetes Mellitus, Type 2"[Mesh] OR "Diabetes Mellitus, Type 2/epidemiology"[Mesh] OR ("type 2 diabet*"[tiab] OR T2D[tiab] OR "diabetes incidence"[tiab] OR incident[tiab] AND diabet*[tiab] OR dysglycem*[tiab] OR "fasting plasma glucose"[tiab] OR HbA1c[tiab] OR "glycated hemoglobin"[tiab] OR hyperglycem*[tiab]))AND("Temperature"[Mesh] OR "Hot Temperature"[Mesh] OR "Urban Heat Island"[tiab] OR "heat wave*"[tiab] OR heatwave*[tiab] OR "apparent temperature"[tiab] OR "heat index"[tiab] OR WBGT[tiab] OR "wet-bulb globe temperature"[tiab] OR temperature[tiab] OR "nighttime temperature"[tiab])AND(Africa South of the Sahara[Mesh] OR (Angola[tiab] OR Benin[tiab] OR Botswana[tiab] OR "Burkina Faso"[tiab] OR Burundi[tiab] OR "Cabo Verde"[tiab] OR Cameroon[tiab] OR "Central African Republic"[tiab] OR Chad[tiab] OR Comoros[tiab] OR Congo[tiab] OR "Democratic Republic of the Congo"[tiab] OR DRC[tiab] OR "Cote d'Ivoire"[tiab] OR "Ivory Coast"[tiab] OR Djibouti[tiab] OR "Equatorial Guinea"[tiab] OR Eritrea[tiab] OR Eswatini[tiab] OR Ethiopia[tiab] OR Gabon[tiab] OR Gambia[tiab] OR Ghana[tiab] OR Guinea[tiab] OR "Guinea-Bissau"[tiab] OR Kenya[tiab] OR Lesotho[tiab] OR Liberia[tiab] OR Madagascar[tiab] OR Malawi[tiab] OR Mali[tiab] OR Mauritania[tiab] OR Mauritius[tiab] OR Mozambique[tiab] OR Namibia[tiab] OR Niger[tiab] OR Nigeria[tiab] OR Rwanda[tiab] OR "Sao Tome"[tiab] OR "Sao Tome and Principe"[tiab] OR Senegal[tiab] OR Seychelles[tiab] OR "Sierra Leone"[tiab] OR Somalia[tiab] OR "South Africa"[tiab] OR "South Sudan"[tiab] OR Sudan[tiab] OR Tanzania[tiab] OR Togo[tiab] OR Uganda[tiab] OR Zambia[tiab] OR Zimbabwe[tiab])))AND (("2000/01/01"[Date - Publication] : "2025/09/12"[Date - Publication]))AND (english[lang] OR french[lang] OR portuguese[lang])AND (Humans[Mesh]) Embase (Elsevier) ('type 2 diabetes mellitus'/exp OR (('type 2' NEAR/3 diabet*):ti,ab OR t2d:ti,ab OR 'diabetes incidence':ti,ab OR dysglycem*:ti,ab OR hba1c:ti,ab OR 'fasting plasma glucose':ti,ab))AND('temperature'/exp OR 'high temperature'/exp OR (heat NEXT/1 wave*):ti,ab OR heatwave*:ti,ab OR 'apparent temperature':ti,ab OR 'heat index':ti,ab OR wbgt:ti,ab OR 'wet-bulb globe temperature':ti,ab OR 'urban heat island':ti,ab OR temperature:ti,ab)AND(('sub-saharan africa'/exp) OR (Angola OR Benin OR Botswana OR 'Burkina Faso' OR Burundi OR 'Cabo Verde' OR Cameroon OR 'Central African Republic' OR Chad OR Comoros OR Congo OR 'Democratic Republic of the Congo' OR DRC OR "Cote d'Ivoire" OR 'Ivory Coast' OR Djibouti OR 'Equatorial Guinea' OR Eritrea OR Eswatini OR Ethiopia OR Gabon OR Gambia OR Ghana OR Guinea OR 'Guinea-Bissau' OR Kenya OR Lesotho OR Liberia OR Madagascar OR Malawi OR Mali OR Mauritania OR Mauritius OR Mozambique OR Namibia OR Niger OR Nigeria OR Rwanda OR 'Sao Tome' OR 'Sao Tome and Principe' OR Senegal OR Seychelles OR 'Sierra Leone' OR Somalia OR 'South Africa' OR 'South Sudan' OR Sudan OR Tanzania OR Togo OR Uganda OR Zambia OR Zimbabwe):ti,ab,kw)AND [english]/lim OR [french]/lim OR [portuguese]/limAND [humans]/limAND [adult]/limAND (py>=2000 AND py<=2025) PRISMA flow Records identified (all sources): 1,026 Duplicates removed: 184 Records screened (title/abstract): 842 Records excluded at T/A: 730 Full-text articles assessed: 112 Full-text excluded (with reasons): 98 No incident outcome (Tier 1) and no validated dysglycemia endpoint (Tier 2): 41 Outside SSA or no SSA-extractable estimate: 19 Inadequate exposure definition/resolution: 16 Prevalence-only design: 12 Wrong diabetes type (type 1 or gestational): 6 Insufficient extractable data: 4 Studies included in qualitative synthesis: 14